Anti-entrapment system

ABSTRACT

An anti-entrapment system for preventing objects from being entrapped by a translating device includes a capacitance sensor positioned adjacent to the translating device and a controller. The sensor has first and second conductors separated by a separation distance and a compressible dielectric element interposed between the conductors. The conductors have a capacitance dependent upon the separation distance. The capacitance of the conductors changes in response to a geometry of the sensor changing as a result of either conductor or the dielectric element deforming in response to a first object touching the sensor. The capacitance of the conductors changes in response to a second conductive object coming into proximity with either conductor. The controller receives a signal from the sensor indicative of the capacitance of the conductors, and controls the translating device as a function of the capacitance of the conductors to prevent the translating device from entrapping either object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an anti-entrapment system provided witha capacitance sensor for preventing entrapment of an object.

2. Background Art

Anti-entrapment systems use various types of sensors to detect pinchingof an object such as a human body part. For example, in automobiles,sensors are used for pinch sensing at electrically operated doors,windows, hatches, decks, hoods, lids, and the like.

A pinch sensor detects pinching an object by a translating device suchas a window, door, sunroof, etc. In operation, the pinch sensorgenerates a pinch sensor signal in response to the object such as aperson's finger being pinched by a translating device such as a windowas the window is closing. In response to the pinch sensor signal, acontroller controls the window to reverse direction and open in order toprevent further pinching of the person's finger. As the window isopening, the person may remove his finger from the window openingbetween the top edge of the window and the window liner.

Motor current sensors, infrared beam sensors, and continuous switchsensors have been used as pinch sensors in anti-entrapment systems. Aproblem with these types of pinch sensors is that they require arelatively large amount of pinching of the object to take place beforethey detect pinching of the object.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide ananti-entrapment system having a sensor that detects a translating devicepinching an object as soon as the translating device has applied arelatively small amount of pinching to the object and/or detects thepresence of an object within an opening which may be closed by thetranslating device in order to prevent any pinching of either object bythe translating device.

In carrying out the above object and other objects, the presentinvention provides an anti-entrapment system for preventing objects frombeing entrapped by a translating device. The anti-entrapment systemincludes a capacitance sensor which is positioned adjacent to atranslating device. The capacitance sensor has first and secondconductors separated by a separation distance and a compressibledielectric element interposed between the conductors. The conductorshave a capacitance dependent upon the separation distance. Thecapacitance of the conductors changes in response to geometry of thecapacitance sensor changing as a result of at least one of theconductors and the dielectric element deforming in response to a firstobject touching the capacitance sensor. The capacitance of theconductors changes in response to a second conductive object coming intoproximity with at least one of the conductors.

Further, in carrying out the above object and other objects, theanti-entrapment system further includes a controller for receiving asignal from the capacitance sensor indicative of the capacitance of theconductors. The controller controls the translating device as a functionof the capacitance of the conductors in order to prevent the translatingdevice from entrapping either object.

The above object and other objects, features, and advantages of thepresent invention are readily apparent from the following detaileddescription of the preferred embodiment(s) when taken in connection withthe accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 a illustrates a block diagram of an anti-entrapment system havinga capacitance sensor in accordance with the present invention;

FIG. 1 b illustrates a block diagram of the anti-entrapment system inwhich the sensor and a controller are integrated;

FIG. 2 illustrates a first embodiment of the sensor of theanti-entrapment system;

FIG. 3 illustrates a cross-sectional view of the sensor taken along theline 3-3 of FIG. 2;

FIG. 4 a illustrates the operation of the sensor for detecting an objectin proximity to the sensor;

FIG. 4 b illustrates the operation of the sensor for detecting an objecttouching the sensor;

FIG. 5 illustrates the placement of the sensor of the anti-entrapmentsystem for use in an automobile door-window environment;

FIG. 6 a illustrates a cross-sectional view of a first placement of thesensor in the automobile door-window environment taken along the line6-6 of FIG. 5;

FIG. 6 b illustrates a cross-sectional view of a second placement of thesensor in the automobile door-window environment taken along the line6-6 of FIG. 5;

FIG. 7 illustrates in greater detail the sensor placement shown in FIG.6B;

FIG. 8 illustrates the placement of the sensor of the anti-entrapmentsystem for use in an automobile sliding-door environment;

FIG. 9 illustrates the placement of the sensor of the anti-entrapmentsystem for use in an automobile sunroof environment;

FIG. 10 illustrates the placement of the sensor of the anti-entrapmentsystem for use in an automobile deck lid environment;

FIGS. 11 a and 11 b illustrate the placement of the sensor of theanti-entrapment system for use in a hatchback environment;

FIG. 12 illustrates the placement of the sensor of the anti-entrapmentsystem for use in an automated bus door environment;

FIG. 13 illustrates the placement of the sensor of the anti-entrapmentsystem for use in an elevator door environment;

FIG. 14 illustrates the placement of the sensor of the anti-entrapmentsystem for use in a garage door environment;

FIG. 15 illustrates the placement of the sensor of the anti-entrapmentsystem for use with an industrial machine;

FIG. 16 illustrates a second embodiment of the sensor of theanti-entrapment system;

FIG. 17 illustrates a cross-sectional view of the sensor shown in FIG.16 taken along the line 17-17 of FIG. 16;

FIG. 18 illustrates a third embodiment of the sensor of theanti-entrapment system;

FIG. 19 illustrates a cross-sectional view of the sensor shown in FIG.18 taken along the line 19-19 of FIG. 18;

FIG. 20 illustrates a fourth embodiment of the sensor of theanti-entrapment system;

FIG. 21 illustrates a cross-sectional view of the sensor shown in FIG.20 taken along the line 21-21 of FIG. 20;

FIG. 22 illustrates a fifth embodiment of the sensor of theanti-entrapment system;

FIG. 23 illustrates a cross-sectional view of the sensor shown in FIG.22 taken along the line 23-23 of FIG. 22;

FIG. 24 illustrates a sixth embodiment of the sensor of theanti-entrapment system;

FIG. 25 illustrates a cross-sectional view of the sensor shown in FIG.24 taken along the line 25-25 of FIG. 24;

FIG. 26 illustrates a seventh embodiment of the sensor of theanti-entrapment system;

FIG. 27 illustrates a cross-sectional view of the sensor shown in FIG.26 taken along the line 27-27 of FIG. 26;

FIG. 28 illustrates an eighth embodiment of the sensor of theanti-entrapment system;

FIG. 29 illustrates a cross-sectional view of the sensor shown in FIG.28 taken along the line 29-29 of FIG. 28;

FIG. 30 illustrates a ninth embodiment of the sensor of theanti-entrapment system;

FIG. 31 illustrates a cross-sectional view of the sensor shown in FIG.30 taken along the line 31-31 of FIG. 30;

FIG. 32 illustrates a cross-sectional view of the placement of thesensor of the anti-entrapment system for use with a tonneau coverenvironment;

FIG. 33 illustrates a top view of the placement of the sensor of theanti-entrapment system for use with the tonneau cover environment;

FIG. 34 illustrates a tenth embodiment of the sensor of theanti-entrapment system;

FIG. 35 illustrates a cross-sectional view of the sensor shown in FIG.34 taken along the line 35-35 of FIG. 34;

FIG. 36 illustrates the placement of the sensor of the anti-entrapmentsystem for use with a double sliding door environment;

FIG. 37 illustrates the placement of the sensor of the anti-entrapmentsystem for use with a single sliding door environment;

FIG. 38 illustrates the placement of the sensor of the anti-entrapmentsystem for use in a double hinged automatic door environment;

FIG. 39 illustrates the placement of the sensor of the anti-entrapmentsystem for use in a single hinged automatic door environment;

FIG. 40 illustrates a cross-sectional view of an eleventh embodiment ofthe sensor of the anti-entrapment system taken along the line 40-40 ofFIG. 41;

FIG. 41 illustrates a profile view of the sensor shown in FIG. 40;

FIG. 42 illustrates a cross-sectional view of a 12^(th) embodiment ofthe sensor of the anti-entrapment system taken along the line 42-42 ofFIG. 43;

FIG. 43 illustrates a profile view of the sensor shown in FIG. 42;

FIG. 44 illustrates a cross-sectional view of a 13^(th) embodiment ofthe sensor of the anti-entrapment system taken along the line 44-44 ofFIG. 45;

FIG. 45 illustrates a profile view of the sensor shown in FIG. 44;

FIG. 46 illustrates a cross-sectional view of a 14^(th) embodiment ofthe sensor of the anti-entrapment system taken along the line 46-46 ofFIG. 47;

FIG. 47 illustrates a profile view of the sensor shown in FIG. 46;

FIG. 48 illustrates a cross-sectional view of a 15^(th) embodiment ofthe sensor of the anti-entrapment system taken along the line 48-48 ofFIG. 49;

FIG. 49 illustrates a profile view of the sensor shown in FIG. 48;

FIG. 50 illustrates a cross-sectional view of a 16^(th) embodiment ofthe sensor of the anti-entrapment system taken along the line 50-50 ofFIG. 51;

FIG. 51 illustrates a profile view of the sensor shown in FIG. 50;

FIG. 52 illustrates a profile view of a 17^(th) embodiment of the sensorof the anti-entrapment system;

FIG. 53 illustrates a cross-sectional view of the sensor shown in FIG.52 taken along the line 53-53 of FIG. 52;

FIG. 54 illustrates a cross-sectional view of an 18^(th) embodiment ofthe sensor of the anti-entrapment system;

FIG. 55 illustrates a cross-sectional view of a 19^(th) embodiment ofthe sensor of the anti-entrapment system;

FIG. 56 illustrates a blown-up view of the sensor shown in FIG. 54;

FIG. 57 illustrates a cross-sectional view of the sensor shown in FIG.54 positioned within the weather seal of a window frame;

FIG. 58 illustrates a graph showing the relationship of proximity signalstrength of a capacitance sensor in accordance with the presentinvention versus dielectric thickness for different object proximitydistances to the capacitance sensor;

FIG. 59 illustrates a graph showing the relationship of proximity signalstrength of a capacitor sensor in accordance with the present inventionversus conductor plate width for different object proximity distancesand different object material types;

FIG. 60 illustrates a preferred embodiment of the capacitance sensor ofthe anti-entrapment system;

FIGS. 61 a and 61 b illustrate views of the capacitance sensor shown inFIG. 60 behaving as a parallel plate capacitor;

FIG. 62 a illustrates the capacitance sensor shown in FIG. 60 operatingin a proximity sensing mode;

FIG. 62 b illustrates the capacitance sensor shown in FIG. 60 operatingin a touch sensing mode;

FIG. 63 illustrates an equivalent circuit for the sensor arrangementshown in FIG. 62 a;

FIG. 64 illustrates a variation of the preferred embodiment of thesensor shown in FIG. 60;

FIGS. 65 a, 65 b, and 65 c illustrate a variation of the preferredembodiment of the sensor shown in FIG. 60;

FIG. 66 illustrates a variation of the preferred embodiment of thesensor shown in FIG. 60;

FIG. 67 illustrates a variation of the preferred embodiment of thesensor shown in FIG. 60;

FIG. 68 illustrates a variation of the sensor embodiment variation shownin FIG. 67;

FIG. 69 illustrates a variation of the preferred embodiment of thesensor shown in FIG. 60;

FIG. 70 illustrates the sensor shown in FIG. 60 incorporated within aweather seal;

FIG. 71 illustrates the anti-entrapment system shown in FIGS. 1 a and 1b in which the controller of the anti-entrapment system is shown ingreater detail;

FIG. 72 illustrates a translating device monitor software routineperformed by the micro-controller of the controller shown in FIG. 71;

FIG. 73 illustrates a system calibration software routine performed bythe micro-controller of the controller shown in FIG. 71;

FIG. 74 illustrates a sensor measurement software routine performed bythe micro-controller of the controller shown in FIG. 71;

FIG. 75 illustrates a read sensor software routine performed by themicro-controller of the controller shown in FIG. 71;

FIG. 76 illustrates a motor monitor software routine performed by themicro-controller of the controller shown in FIG. 71;

FIG. 77 illustrates a motor current software routine performed by themicro-controller of the controller shown in FIG. 71; and

FIG. 78 illustrates a motor commutation software routine performed bythe micro-controller of the controller shown in FIG. 71.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to FIG. 1 a, an anti-entrapment system 10 in accordancewith the present invention is shown. Anti-entrapment system 10 includesa sensor 12 and a controller 14. Sensor 12 is generally a capacitancesensor that is operable to detect touching by an object 16 to the sensorand/or the presence (i.e., proximity) of an object 16 near the sensor.In response to an object 16, including human body parts, touching sensor12, the capacitance of the sensor changes. Likewise, in response to anelectrically conductive object 16, including human body parts, comingwithin the proximity of sensor 12, the capacitance of the sensor changeseven without the object actually touching, or applying any force, to thesensor. This provides for zero force detection of a human body partbefore contact to sensor 12 is made by the body part. As such, sensor 12is a contact (i.e., touch) and a non-contact (i.e., proximity) sensor.

Controller 14 controls a motor 18 associated with a translating device20 such as a window, sliding door, sunroof, etc. in order to move thetranslating device between opened and closed positions. Controller 14controls motor 18 to move window 20 in an opening direction when anopening provided by the window is desired. Similarly, controller 14controls motor 18 to move window 20 in a closing direction in order toclose off the window opening.

Generally, an operator actuates a switch to have controller 14 controlthe opening and closing of window 20. Such a switch may be configured toprovide express-up (i.e., express close) and express-down (i.e., expressopen) functionality such that a single switch actuation (as opposed to acontinuous actuation) causes controller 14 to control window 20 untilthe window has fully moved into its opened or closed position.

Sensor 12 is placed adjacent to a window opening provided by window 20.Sensor 12 monitors the window opening to determine whether an object 16such as a person's hand or finger is near or extends through the windowopening. As can be appreciated, a problem with object 16 extendingthrough the window opening is that when window 20 moves in the closingdirection and closes off the window opening, the window will pinch theobject unless the object is removed from the window opening.

Sensor 12 is placed adjacent to the window opening such that object 16touches the sensor and/or becomes in close proximity to the sensor ifthe object is caught between the window opening and window 20 and isabout to be pinched by the window. Sensor 12 generates a pinch sensorsignal 21 in response to object 16 touching the sensor and generates aproximity sensor signal 23 in response to the object being in closeproximity to the sensor. Sensor 12 provides pinch and proximity sensorsignals 21, 23 to controller 14. In response to receiving either ofpinch and proximity sensor signals 21, 23, controller 14 controls window20 via motor 18 accordingly.

For instance, if the operator has actuated the switch to have controller14 close window 20 and the window is now closing (for example, when thewindow is in express-up operation), the controller controls the windowto stop closing and then open in response to a detection by sensor 12 ofobject 16 within the window opening. Reversing the direction of window20 and opening the window causes the window opening to increase in sizein order to prevent any pinching of the object and to give time for theobject to be removed from the window opening. Similarly, if sensor 12detects the presence of object 16 within window opening, then controller14 prevents window 20 from subsequently moving in the closing directionuntil the object has been removed from the window opening.

Referring now to FIG. 1 b, sensor 12 and controller 14 may be integratedwith one another to form a sensor/controller 13. Sensor/controller 13effectively provides the same function as non-integrated sensor 12 andcontroller 14. As such, in this document, the description regardingsensor 12 and controller 14 also refers to the sensor and controllerfunctionality provided by sensor/controller 13.

Controller 14 can have switch inputs, communications capability withother sensors and controllers, and various outputs for controlling andmonitoring various aspect of window 20. For instance, controller 14 canhave sensor inputs for motor 18 as designated by line 19 in FIG. 1 a orother moving members to determine the position, direction of movement,speed of movement, etc. of window 20. Such sensor inputs could be forreceiving signals from Hall Effect sensors and the like such as opticand resistive sensors.

In the case of controller 14 receiving sensor signals 19 responsive tomotor 18 or other moving members, the controller would have additionalanti-entrapment capabilities by making use of motor current and/orcommutator pulses and/or sensor signals from Hall (or other type)sensors. This would have the added benefit of being able to detectobstructions while the moving member and the obstruction are too faraway from sensor 12 to be sensed by the sensor.

Referring now to FIGS. 2 and 3, a first embodiment of sensor 12 isshown. Sensor 12 includes a flexible center conductive element or core22 coaxially surrounded by a non-conductive compressible element orlayer 26 that is in turn coaxially surrounded by a flexible outerconductive element or layer 24. Non-conductive compressible layer 26separates conductive core 22 and conductive layer 24. Conductive core 22is electrically grounded for sensor 12. An elastomeric overcoat 28covers conductive layer 24.

Conductive core 22 and conductive layer 24 are made from conductivematerials such as aluminum, copper, and the like. Conductive core 22 andconductive layer 24 may also be made from materials such as nylon,polyester, and the like that have been plated or metalized with aconductive material such as aluminum, copper, nicked, and the like.Conductive core 22 and conductive layer 24 each may be a braided mesh ora metalized woven fabric which gives the conductive core and theconductive layer their flexibility. Conductive core 22 and conductivelayer 24 may also be a plated woven fabric that has as a metalizationcoating of copper, for proper conductivity, with a nickel coating overthe copper, for corrosion resistance. Non-conductive compressible layer26 may be an EPDM closed cell foam having a high dielectric constant anda low compressible force. The dielectric constant and/or compressibilityof non-conductive layer 26 may be changed by using different types ofmaterials. For instance, non-conductive layer 26 may simply be air.Elastomeric overcoat 28 may be made from elastomeric rubbers, likevinyl, thermo-plastic elastomers such as Santoprene, Neoprene, Buna N,and the like. Elastomeric overcoat 28 could also be felt fabric and thelike. Elastomeric overcoat 28 may be semi-rigid, flexible, and/orcompressible and may incorporate sealing elements, adhesives, and otherattachments.

Referring now to FIG. 4 a with continual reference to FIG. 1, theoperation of sensor 12 for determining the presence of an object withinthe proximity of the sensor will now be described in more detail. Sensor12 is typically mounted to a fixed assembly such as an automobile windowbody panel 32. Sensor 12 can also be embodied in the automobile windowweather-strip and the like. In FIG. 4 a, an electrically conductiveobject 30 such as a human body part is placed in the window openingbetween window 20 and sensor 12. As shown, the window opening issufficiently large enough such that object 30 can move freely in thewindow opening without being pinched by window 20. If the window openingbecomes smaller as the result of window 20 closing such that object 30becomes proximal to sensor 12 and enters the capacitive fieldsurrounding conductive layer 24, then the capacitance of the sensorchanges.

Sensor 12 then generates proximity sensor signal 23 indicative of thischange in capacitance to controller 14. Controller 14 processesproximity sensor signal 23 to determine that the capacitance of sensor12 has changed as a result of object 30 being proximal to sensor 12 andis about to be pinched by window 20. Controller 14 then controls motor18 to open window 20 and reverse its movement away from window bodypanel 32 thereby increasing the window opening and allowing object 30 tobe removed from the window opening without any pinching of the object bythe window.

Referring now to FIG. 4 b with continual reference to FIG. 1, theoperation of sensor 12 for detecting an object touching the sensor willnow be described in more detail. In FIG. 4 b, window 20 starts to closein the direction of the arrow towards window body panel 32 and thewindow opening becomes smaller such that a non-electrically conductiveobject 31 is between sensor 12 and window 20 and touches the sensor. Inresponse to object 31 touching sensor 12, the sensor compresses suchthat the distance between conductive core 20 and conductive layer 24becomes smaller. As a result of this distance becoming smaller, thecapacitance of sensor 12 changes.

Sensor 12 then generates pinch sensor signal 21 indicative of thischange in capacitance to controller 14. Controller 14 processes pinchsensor signal 21 to determine that the capacitance of sensor 12 haschanged as a result of object 31 touching the sensor and is about to bepinched by window 20. Controller 14 then controls motor 18 to openwindow 20 and reverse its movement away from window body panel 32thereby increasing the window opening and allowing object 31 to beremoved from the window opening without any pinching of the object bythe window. It is to be appreciated that an electrically conductiveobject such as object 30 may also touch sensor 12 and, in this case, thesensor likewise compresses and generates a pinch sensor signal 21indicative of the resulting change in capacitance.

As will be explained in greater detail with respect to FIG. 71,controller 14 may include an electronic micro-processor(micro-controller) having a digital to analog (DAC) converter. The DACconverter allows for the subtraction (or an addition) of an offsetvoltage to allow for greater amplification of pinch and proximity sensorsignals 21, 23. Alternative embodiments could include analog waveformgeneration, such as a triangle wave, to accomplish the determination ofthe magnitude of the offset voltage for subsequent subtraction (oraddition) thereof. The microprocessor may execute software for filteringand may use algorithms for adaptive threshold detection enablingdetermination of object proximity to sensor 12 or compression of thesensor as a result of an object touching the sensor. The microprocessormay be substituted with discrete electronic, hybrid electronics, or acustom application specific integrated circuit that may includemicroprocessor core analog and digital circuitry.

Controller 14 may also incorporate system functions such as functions ofa vehicle door system. Such door system functions include functionsassociated with power mirrors, such as movement, electro-chromaticcontrol, turn signal indication, and heating control; power door locks;keyless entry systems; personalization settings, such as driver 1 anddriver 2; and the like. In this instance, controller 14 uses amicro-controller with serial communications, via wires, optic fibers, orwireless such as RF wireless, to communicate with other control moduleslocated within a vehicle. The use of such a controller eliminates theredundancy of multiple modules in a door system. In this instance,controller 14 can be integrated with the window lift motor, or be aseparate module that is wired to items controlled by the module.

Controller 14 may also incorporate other system functions based onmounting locations other than a vehicle door. Functions associated withmounting locations such as the dashboard, center console, or seat may beintegrated into the module. Functions such as steering wheel andsteering column adjustments, seat position settings, seat heating andcooling, global positioning and Internet communications, and pedaladjustment.

Referring now to FIG. 5, the placement of sensor 12 of anti-entrapmentsystem 10 for use in an automobile door-window environment 33 is shown.Automobile door-window environment 33 includes a door 34 and a windowbody panel 32. Window 20 automatically moves down and up to open andclose with respect to window body panel 32. In an opened position,window 20 forms a window opening 35 between a top edge 36 of the windowand window body panel 32. Sensor 12 is placed along window body panel32. As described above, sensor 12 is operable to detect the presence ofan object extending through window opening 35 that is adjacent to thesensor and/or is touching the sensor. Such capability enables sensor 12to function in conjunction with controller 14 to prevent window 20 frompinching the object as the window closes off window opening 35.

FIG. 6 a illustrates a cross-sectional view of a first placement ofsensor 12 relative to window 20 and window body panel 32. Sensor 12 isplaced within the interior of the automobile adjacent to window bodypanel 32 and a window weather strip 37. Window weather strip 37 isattached to window body panel 32 and seals off window 20 when the windowmoves to its fully closed position as shown in FIG. 6A.

FIG. 6 b illustrates a cross-sectional view of a second placement ofsensor 12 relative to window 20 and window body panel 32. Sensor 12 isformed integral with a window weather strip 38 which is attached towindow body panel 32. FIG. 7 illustrates in greater detail theintegration of sensor 12 within window weather strip 38.

Referring now to FIG. 8, the placement of sensor 12 of anti-entrapmentsystem 10 for use in an automobile sliding-door environment 40 is shown.Automobile sliding-door environment 40 includes an electrically operatedsliding door 42 and an automobile door body panel 44. Sliding door 42moves horizontally to open and close with respect to door body panel 44.In an opened position, sliding door 42 forms a door opening 46 between aleading edge 47 of the sliding door and door body panel 44. Sensor 12 isplaced along door body panel 44 in a manner analogous to the placementof the sensor as shown in either FIG. 6 a or FIG. 6 b. Sensor 12 mayalso be mounted on sliding door 42 instead of door body panel 44. Sensor12 detects the presence of an object extending through sliding dooropening 46 upon the object being adjacent to the sensor and/or touchingthe sensor. In response to sensor 12 detecting an object extendingthrough door opening 46, controller 14 prevents sliding door 42 frompinching the object as the sliding door moves in the direction of theillustrated arrow and closes off door opening 46.

Referring now to FIG. 9, the placement of sensor 12 of anti-entrapmentsystem 10 for use in an automobile sunroof environment 50 is shown.Automobile sunroof environment 50 includes an electrically operatedsliding sunroof 52 and an automobile roof 54. Sunroof 52 moveshorizontally with respect to roof 54 to form and close an opening 56 inthe roof. In an opened position, sunroof 52 forms roof opening 56between a leading edge 57 of the sunroof and roof 54. Sensor 12 isplaced along roof 54 in a manner analogous to the placement of thesensor as shown in either FIG. 6 a or FIG. 6 b. As described above,sensor 12 is operable to detect the presence of an object extendingthrough roof opening 56 upon the object being adjacent to the sensorand/or touching the sensor. Such capability enables sensor 12 tofunction in conjunction with controller 14 to prevent sunroof 52 frompinching the object as the sunroof closes off roof opening 56.

Referring now to FIG. 10, the placement of sensor 12 of anti-entrapmentsystem 10 for use in an automobile deck lid environment 60 is shown.Automobile deck lid environment 60 includes an electrically operateddeck lid 62. Deck lid 62 opens and closes with respect to an automobiletrunk 64. Sensor 12 is placed along an edge 65 of trunk 64 in a manneranalogous to the placement of the sensor as shown in either FIG. 6 a orFIG. 6 b. As described above, sensor 12 detects the presence of anobject extending from the exterior of trunk 64 into the interior of thetrunk as a result of such object being adjacent to the sensor and/ortouching the sensor. Sensor 12 provides appropriate sensor signals 21,23 to controller 14 in order to prevent deck lid 62 from pinching theobject as the deck lid closes off trunk 64.

In addition to the automobile applications described above,anti-entrapment system 10 may also be used in other automobileapplications including those involving tonneau covers and hatchbackdoors. For instance, as shown in FIGS. 11 a and 11 b, the placement ofsensor 12 for use in an automobile hatchback environment 66 is shown.Automobile hatchback environment 66 includes a hatch 67 and anautomobile body panel 68. A cylinder 69 connects hatch 67 and automobilebody panel 68. Cylinder 69 includes a piston rod which extends to movehatch 67 to an opened position with respect to body panel 68 andcontracts to move the hatch to a closed position with respect to thebody panel (the hatch in the closed position is shown as a dotted linein FIG. 11 a). Sensor 12 is placed along body panel 68. Sensor 12detects the presence of an object extending in the opening between hatch67 and body panel 68 that is adjacent to the sensor and/or is touchingthe sensor. Controller 14 is then able to control cylinder 69 to preventhatch 67 from pinching the object as the hatch is being closed.

Referring now to 12, the placement of sensor 12 for use in an automatedbus door environment 70 is shown. Automated bus door environment 70includes a pair of electrically operated doors 72 and 74. Hinges 76power doors 72 and 74 to automatically open and close. When closing,door 72 closes prior to door 74 such that door 74 overlaps door 72 whenboth doors are closed. Sensor 12 is placed along an edge 75 of door 72and may be incorporated into a door weather strip. Sensor 12 detects thepresence of an object extending into the door opening as a result ofsuch object being adjacent to the sensor and/or touching the sensor.Sensor 12 functions in conjunction with controller 14 to prevent door 74from pinching the object as door 74 closes following the closing of door72.

In addition to automobile applications, anti-entrapment system 10 mayalso be used in industrial applications. For instance, FIGS. 13 and 14illustrate the placement of sensor 12 of anti-entrapment system 10 foruse in an elevator door environment 80 and a garage door environment 85,respectively. Elevator door environment 80 is a specific application ofa general sliding door environment. In elevator door environment 80,sensor 12 is placed on a leading edge of either elevator door 82.Elevator doors 82 are shown partially opened with an elevator dooropening 84 therebetween. Sensor 12 detects the presence of an objectextending between elevator doors 82 as a result of such object beingadjacent to the sensor and/or touching the sensor. Sensor 12 generatesan appropriate sensor signal 21, 23 for controller 14 in order toprevent elevator doors 82 from pinching the object as the doors slideclose.

In garage door environment 85, sensor 12 is placed along a bottom edge86 of a garage door 87. Garage door 87 is shown partially opened with agarage door opening 88 between bottom edge 86 of the garage door and thedriveway 89 leading into the garage. Sensor 12 detects the presence ofan object extending within garage door opening 88 as a result of suchobject being adjacent to the sensor and/or touching the sensor. Sensor12 generates an appropriate sensor signal 21, 23 for controller 14 inorder to prevent garage door 87 from pinching the object as the garagedoor closes.

FIG. 15 illustrates the placement of sensor 12 of anti-entrapment system10 for use with an industrial machine 90. Industrial machine 90 includesa press machine ram mechanism 91 having an upper press tooling die 92. Alower press tooling die 93 is fixed on a press machine platen 94. Rammechanism 91 is movable to force upper press tooling die 92 againstlower press tooling die 93. During operation, a press operator facesindustrial machine 90 in the direction of arrow 95. Sensor 12 is placedwithin a cavity 96 formed on a front edge 97 of lower press tooling die93. As such, sensor 12 is positioned to face the press operator. Withincavity 96, sensor does not come into contact with upper press toolingdie 92 as this tooling die closes on lower press tooling die 93. Duringoperation of industrial machine 90, sensor 12 detects the presence of anobject touching the sensor and/or the presence of a conductive objectsuch as a finger within the proximity of the sensor. Sensor 12 thengenerates an appropriate sensor signal 21, 23 for controller 14 in orderto prevent upper press tooling die 92 from slamming on a foreign objectwithin the vicinity of lower press tooling die 93.

Referring now to FIG. 16, a sensor 100 in accordance with a secondsensor embodiment is shown. Sensor 100 is similar to sensor 12 butincludes a third flexible conductive element 102 that coaxiallysurrounds first and second flexible conductive elements 104, 106. Sensor100 includes a non-conductive compressible coaxial element 108surrounding first conductor 104 and a non-conductive compressiblecoaxial element 110 surrounding second conductor 106. An outerelastomeric coating 112 coaxially surrounds third conductor 102.Non-conductive compressible elements 108 and 110 may be made from thesame closed cell foam or other compressible material. Like first andsecond conductors 104, 106, third conductor 102 may also be a braidedwire mesh made from a conductive material. Second conductor 106 iselectrically grounded.

Referring now to FIG. 17, a cross-sectional view of sensor 100 is shown.A semi-rigid elastomer 110 is used in place of coaxial non-conductivecompressible layer 110. Semi-rigid elastomer 110 allows for fasterchange in capacitance of first and second conductors 104, 106 in theevent of an object being in contact with outer coating 112. The distancebetween third and second conductors 102, 106 and the proximity of anelectrically conductive object to third conductor 102 determine thecapacitance of the third and second conductors. The distance betweenfirst and second conductors 104, 106 determine the capacitance of thefirst and second conductors. Thus, sensor 100 is a dual-purpose sensorin that it can detect an object in proximity to the sensor and it candetect an object touching the sensor as a function of the correspondingchange in capacitance.

Referring now to FIGS. 18 and 19, a sensor 120 in accordance with athird sensor embodiment is shown. Sensor 120 includes two longitudinallyparallel flexible conductor core elements 122 and 124 separated by adistance. Two non-conductive compressible coaxial elements 126 and 128(or semi-rigid elastomers) individually surround respective conductorcore elements 122 and 124. Two flexible conductor elements 130 and 132which are separated by a distance coaxially surround respectivenon-conductive compressible elements 126 and 128. A semi-rigidelastomeric outer coating 134 encases conductive elements 130 and 132.

Sensor 120 is essentially two sensors 136 and 138. Sensor 136 includeselements 122, 126, 130, and 134. Sensor 138 includes elements 124, 128,132, and 134. Sensor 136 is configured as a contact sensor (i.e., pinchsensor) such that an object must be in contact with the sensor to causethe distance between conductor elements 122 and 130 to be reducedthereby causing a change in capacitance between conductor elements 122and 130 that can be used by controller 14. As such, outer conductorelement 130 is electrically grounded.

Sensor 138 is configured as a non-contact sensor (i.e., proximitysensor) such that an electrically conductive object that is proximal toouter conductor element 132 causes a change in capacitance betweenconductor elements 124 and 132 that can be used by controller 14. Assuch, inner conductor element 124 is electrically grounded. Thus, sensor120 detects objects in contact with sensor 120 as well as detectselectrically conductive objects in proximity to sensor 120.

Referring now to FIGS. 20 and 21, a sensor 140 in accordance with afourth sensor embodiment is shown. Sensor 140 includes twolongitudinally parallel flexible conductor elements 142 and 144separated by a distance. Two compressible coaxial elements 146 and 148(or semi-rigid elastomers) individually surround respective conductorcore elements 122 and 124. Two metal braided flexible conductor elements150 and 152 which are separated by a distance coaxially surroundrespective non-conductive compressible elements 146 and 148. Asemi-rigid elastomeric outer coating 154 encases conductor elements 150and 152.

Sensor 140 is essentially two sensors 156 and 158. Sensor 156 includeselements 142, 146, 150, and 154. Sensor 158 includes elements 144, 148,152, and 154. As shown in FIG. 21, outer coating 154 is configured toprovide for an entry port 157 for receiving a top edge of a translatingdevice 20 such as a window when the window moves in a closing directionto the closed position. In the closed position, sensors 156 and 158 arelocated on respective sides of window 20. As such, sensor 140 providesdetection of objects that are proximal and/or in contact from multipledirections.

Referring now to FIGS. 22 and 23, a sensor 160 in accordance with afifth sensor embodiment is shown. Sensor 160 includes an inner flexibleconductor 162. A hollow non-conductive flexible spanner 164 holds innerflexible conductor 162 to form lower and upper spanner spaces 166 and168. Spanner spaces 166 and 168 are filled with air or other dielectricmedium. A metal braided outer conductor element 170 coaxially surroundsspanner 164. A semi-rigid elastomer outer jacket 172 encases conductorelement 170. Sensor 160 registers a change in capacitance whenever thedistance between outer conductor element 170 and inner conductor element162 changes as a result of an object touching outer jacket 172 and/or asa result of an electrically conductive object coming into proximity withthe outer conductor.

Referring now to FIGS. 24 and 25, a sensor 180 in accordance with asixth sensor embodiment is shown. Sensor 180 includes first and secondflexible conductive metal wires 182 and 184. A non-conductive flexiblespanner 186 holds first conductor 182. A conductive elastomeric outerjacket 188 having a hollow interior holds and encases second conductor184 and holds each end of spanner 186. Spanner 186 divides the interiorof outer jacket 188 into two spaces 190 and 192. Spaces 190 and 192 arefilled with air or other dielectric medium. Sensor 180 registers achange in capacitance whenever the distance between first and secondwires 182 and 184 changes as a result of an object touching outer jacket188 and/or as a result of an electrically conductive object coming intoproximity with either of wires 182 or 184.

Skipping to FIGS. 34 and 35, a sensor 300 in accordance with a tenthsensor embodiment is shown. Sensor 300 includes first and secondflexible conductive metal wires 302 and 304. A conductive flexibleelastomer 303 holds first conductor 302. A non-conductive flexiblespanner 306 holds and encases conductive elastomer 303. A conductiveelastomeric outer jacket 308 having a hollow interior holds and encasessecond conductor 304 and holds each end of spanner 306. Spanner 306divides the interior of outer jacket 308 into two spaces 310 and 312.Spaces 310 and 312 are filled with air or other dielectric medium.Sensor 300 registers a change in capacitance whenever the distancebetween first and second conductors 302 and 304 changes as a result ofan object touching outer jacket 308 and/or as a result of anelectrically conductive object coming into proximity with either ofconductors 302 or 304.

Referring now back to FIGS. 26 and 27, a sensor 200 in accordance with aseventh sensor embodiment is shown. Sensor 200 includes a flexibleconductor element 202 encased by a compressible non-conductive elastomer204. Elastomer 204 rests on a metal frame 206 such as a vehicle frame.Metal frame 206 essentially acts as a second conductor element. As such,sensor 200 registers a change in capacitance whenever the distancebetween conductor element 202 and metal frame 206 changes as a result ofan object touching elastomer 204 and/or as a result of an electricallyconductive object coming into proximity with conductor element 202.

Referring now to FIGS. 28 and 29, a sensor 220 in accordance with aneighth sensor embodiment is shown. Sensor 220 includes a continuousnon-ending flexible metal braid conductor element 222. Conductor element222 defines an interior 224 which is filled with air or other dielectricmedium. A compressible non-conductive elastomer 226 encases conductorelement 222 and its interior 224. Elastomer 226 rests on a metal frame228 which acts as a second conductor element. Sensor 220 registers achange in capacitance whenever the distance between at least a portionof conductor element 222 and metal frame 228 changes as a result of anobject touching elastomer 226 and/or as a result of an electricallyconductive object coming into proximity with conductor element 222.

Referring now to FIGS. 30 and 31, a sensor 240 in accordance with aninth sensor embodiment is shown. Sensor 240 includes inner and outerflexible metal braided conductor elements 242 and 244. Inner conductorelement 242 surrounds a first non-conductive compressible foam element246. Outer conductor element 244 surrounds a second non-conductivecompressible foam element 248. A semi-rigid elastomeric outer jacket 250surrounds second conductor element 244. As best shown in FIG. 31, innerand outer conductor elements 242 and 244 are continuous non-endingelements. Inner conductor element 242 is shaped in a given endlessconfiguration to enable omni-directional proximity sensing capability.As inner conductor element 242 is flexible, its shape may be conformedto provide the desired omni-directional proximity sensing.

Referring now to FIGS. 32 and 33, the placement of a sensor (such assensor 12) of anti-entrapment system 10 for use in a tonneau coverenvironment 260 is shown. Tonneau cover environment 260 includes anelectrically operated tonneau cover 262. Tonneau cover 262 includes anouter tonneau cover 264 and an inner tonneau cover 266. Tonneau cover262 includes a sensor carrier 268 for holding sensor 12. As shown inFIG. 33, sensor carrier 268 holds sensor 12 along a majority of theperiphery of tonneau cover 262 up to the location of a duckbill 272.Tonneau cover 262 opens and closes with respect to a bed wall 270. In amanner as described above, sensor 12 detects the presence of an objectadjacent to tonneau cover 262 as a result of such object being adjacentto the sensor and/or touching the sensor. Sensor 12 provides appropriatesensor signals to controller 14 in order to tonneau cover 262 frompinching the object as the tonneau cover closes.

Referring now to FIGS. 36 and 37, the placements of a sensor (such assensor 12) of anti-entrapment system 10 for use in double and singlesliding door environments 320 and 340 are respectively shown. Double andsingle sliding door environments 320 and 340 are typically located ingrocery stores and the like. In double sliding door environment 320,sensor 12 is placed on a leading edge of either sliding door 322 or 324.Sliding doors 322 and 324 are shown partially opened with a sliding dooropening 326 therebetween. Sensor 12 detects the presence of an objectextending between sliding doors 322 and 324 as a result of such objectbeing adjacent to the sensor and/or touching the sensor. Sensor 12generates an appropriate sensor signal 21, 23 for controller 14 in orderto prevent sliding doors 322 and 324 from pinching the object as thedoors slide close.

Single sliding door environment 340 includes a sliding door 342 and adoor body panel 344. Sliding door 342 moves horizontally to open andclose with respect to door body panel 344. In an opened position,sliding door 342 forms a door opening 346 between a leading edge 347 ofthe sliding door and door body panel 344. Sensor 12 is placed along doorbody panel 344 in a manner analogous to the placement of the sensor asshown in either FIG. 6A or FIG. 6B. Sensor 12 may also be mounted onsliding door 342 (as shown in FIG. 37) instead of door body panel 344.Sensor 12 detects the presence of an object extending through slidingdoor opening 346 that is adjacent to the sensor and/or is touching thesensor. In response to sensor 12 detecting an object extending throughdoor opening 346, controller 14 prevents sliding door 342 from pinchingthe object as the sliding door moves in the direction of the illustratedarrow and closes off door opening 346.

Referring now to FIGS. 38 and 39, the placements of a sensor (such assensor 12) of anti-entrapment system 10 for use in double and singlehinged automatic door environments 360 and 380 are respectively shown.Double and single hinged automatic door environments 360 and 380 aretypically located in grocery stores and the like. In double hingedautomatic door environment 360, sensor 12 is affixed to a sealingsurface 362 of either hinged automatic door 364 or 366. Hinged doors 364and 366 are shown partially opened with a sliding door opening 368therebetween. Sensor 12 detects the presence of an object extendingbetween hinged doors 364 and 366 as a result of such object beingadjacent to the sensor and/or touching the sensor. Sensor 12 generatesan appropriate sensor signal 21, 23 for controller 14 in order toprevent hinged automatic doors 364 and 366 from pinching the object asthe doors swing to a closed position.

In single hinged automatic door environment 380, sensor 12 is affixed toa sealing surface of a hinged automatic door 382 which closes withrespect to a surface of a wall 384. In an opened position, door 382forms a door opening 386 between a leading edge 387 of the door and wallsurface 384. Sensor 12 is placed along wall surface 384 or on leadingedge 387 of door 382. Sensor 12 detects the presence of an objectextending through door opening 386 that is adjacent to the sensor and/oris touching the sensor in order to enable controller 14 to prevent door382 from pinching the object as the door swings shut.

Referring now to FIGS. 40 and 41, a sensor 388 in accordance with aneleventh sensor embodiment is shown. In general, sensor 388 is a contacttype sensor with external over travel capability to prevent high forces.When pressure is applied to a non-conductive elastomer outer jacket 391,a first conductive wire 389, sheathed inside a first conductiveelastomer carrier 390, moves toward a second conductive wire 392,sheathed inside a second conductive elastomer carrier 395. A portion ofelastomer outer jacket 391 is positioned on an elastomer material 394.

To achieve low force requirements and allow switch movement withelectrical contact, an air space 393 is positioned between sheathedfirst and second conductive wires 389 and 392. After sheathed conductivewires 389 and 392 make contact signaling an obstruction to controller14, elastomer material 394 is allowed to compress, thus providing anover-travel feature to prevent system inertia from the closure apparatuscausing high forces against an obstruction. To this end, elastomermaterial 394 is a foam or any elastomer material formulated with aslightly higher compression force compared to the compression force tochange air space 393 between sheathed conductive wires 389 and 392.

Referring now to FIGS. 42 and 43, a sensor 396 in accordance with a12^(th) sensor embodiment is shown. In general, sensor 396 is a contacttype sensor with internal over travel capability to prevent high forces.When pressure is applied to a non-conductive elastomer outer jacket 400,a first conductive wire 397, sheathed inside a first conductiveelastomer carrier 401, begins to move toward a second conductive wire398, which is sheathed inside a second conductive elastomer carrier 402.A conductive elastomer material 399 is positioned between sheathedconductive wires 397 and 398. Conductive elastomer material 399 can befoam or any elastomer material formulated to allow for low force. Airspaces 403 and 404 are positioned between sheathed conductive wires 397and 398 and conductive elastomer material 399.

Air spaces 403 and 404 change as pressure is applied to or removed fromnon-conductive elastomer outer jacket 400. When pressure applied tonon-conductive elastomer outer jacket 400 moves sheathed conductivewires 397 and 398 to completely close air spaces 403 and 404, electricalcontact is made with conductive elastomer material 399, therebycompleting an electrical circuit and signaling an obstruction tocontroller 14. After switch contact has been made, conductive elastomermaterial 399 can continue to compress, thus providing an over-travelfeature to prevent system inertia from the closure apparatus causinghigh forces against an obstruction.

Referring now to FIGS. 44 and 45, a sensor 405 in accordance with a13^(th) sensor embodiment is shown. In general, sensor 405 is acombination proximity/displacement sensor with an internal fabricconductive element that can also be used as a heating element andtemperature sensor. When pressure is applied to a conductive elastomerouter jacket 406, spaces 410 and 411 compress to move the conductiveelastomer outer jacket toward a conductive fabric 407 which is sheathedinside a non-conductive elastomer carrier 408. To this end, spaces 410and 411 can be air, foam, or any dielectric material formulated to allowfor low force.

A conductive wire 409 is used to make an electrical connection forconductive elastomer outer jacket 406. Sensor 405 registers a change incapacitance whenever the distance between conductive fabric 407 andconductive elastomer outer jacket 406 changes as a result of an objecttouching the outer jacket and/or as a result of an electricallyconductive object coming into proximity with the outer jacket. Thechange in capacitance is signaled to controller 14.

Conductive fabric 407 may be used as a heating element when theanti-pinch strip system is inactive. The heating element function can beused to heat sensor 405, which may be being used as a weather seal,keeping conductive elastomer carrier 408 and dielectric spaces 410 and411 pliable in cold weather conditions. It is a goal to have the weatherseal properties maintained to application compliance standards whileheated. Additionally, the heated weather seal could be used to preventthe window or sliding panel from freezing and/or to aid in thawing afrozen window or sliding panel while in the closed position. Conductivefabric 407 would be engaged as a heating element when powered by relaysturned on by controller 14 with inputs from a temperature sensor, whichcould be from the vehicle outside temperature sensor. The temperatureinput could also originate from a separate temperature sensor located ona device inside the vehicle door, or anywhere else outside the vehicle.

The temperature setting to turn on conductive fabric 407 heating elementis optional, but would likely be set for temperatures at or below 40° F.where cold weather pliability is required. When the set temperature isreached, controller 14 will turn conductive fabric 407 heater element onto make the weather seal pliable. The circuit in controller 14 can alsobe configured to automatically cycle conductive fabric 407 heaterelement on and off after the desired pliability is achieved tothereafter maintain pliability.

By using relays or transistors the heater element 407 can be poweredsuch that an appropriate amount of current flows through the element.The current flow through the resistive element will produce the requiredamount of heat following the well known equation Power (Watts)=I²×R. Thepower can be applied for a given amount of time and then removed. Duringthe time power is removed, the heating element 407 can be connected to acircuit that provides a small amount of current flow through the elementand through a series connected resistor.

Heating element 407 and the series connected resistor form a voltagedivider. The voltage that is developed can then be interpreted by amicroprocessor, or other device such as an op-amp, to determine thetemperature of heating element 407. If the temperature is below adetermined set-point, heating element 407 can again be connected suchthat power is applied to it increasing the amount of heat generated.After the temperature sensor determines that the temperature is abovethe set point, controller 14 will turn off the relays or transistorsproviding power to conductive fabric 407 heater element.

Alternatively, controller 14 can be configured to inhibit a user inputcommand to open a window or sliding panel when, anytime during the timeof heating conductive fabric 407, no window or panel movement is sensed,indicating a stalled motor condition such as may be caused by ice buildup in the weather seal. During such an event, controller 14 continues toinhibit user commands to open the window or sliding panel untilconductive fabric 407 heater element inside the weather seal hasachieved a temperature sufficient to free the window or sliding panel.Controller 14 could be configured to recognize the above condition fromtemperature sensor inputs at all times, including when vehicle ignitionand/or other vehicle power is off. Implementation of this function couldreduce warranty costs related to the window or sliding panel drivemechanism, seals, and motor.

Alternatively, conductive fabric 407 could be used as a heating elementinside a weather seal not using an anti-pinch strip system. In thiscase, controller 14 is configured to only control the heating elementfunction as described above. The controlling function could also beintegrated as part of other electronics being employed within theapplication system.

Alternatively, conductive fabric 407 could be used as a temperaturesensor, either as a stand-alone sensor, or in combination with theanti-pinch system. The function to switch between temperature sensingand anti-pinch sensing would be configured through controller 14. Thetemperature sensing function of conductive fabric 407 could be used toprovide the same temperature inputs required to operate the anti-pinchsystem as described above.

Referring now to FIGS. 46 and 47, a sensor 412 in accordance with a14^(th) sensor embodiment is shown. In general, sensor 412 is acombination proximity/displacement sensor with conductive fabricattached to an outside profile. The conductive fabric can be used as aheating element and temperature sensor. When pressure is applied to anon-conductive elastomer outer jacket 413, a space 417, compresses tomove a first conductive fabric 414, attached externally tonon-conductive outer jacket 413 and covered with flexible non-conductiveflocking material 415, towards a second conductive fabric 416. To thisend, space 417 is air, foam, or any dielectric material formulated toallow for low force.

Sensor 412 registers a change in capacitance whenever the distancebetween first conductive fabric 414 and second conductive fabric 416changes as a result of an object touching non-conductive flockingmaterial covering 415 and/or as a result of an electrically conductiveobject coming into proximity with first conductive fabric 414. Thechange in capacitance is signaled to controller 14.

Conductive fabric 414 may be used as a heating element when theanti-pinch strip system is inactive. The heating element function can beused to heat sensor 412, which may be being used as a weather seal,keeping elastomer outer jacket 413, non-conductive flocking material415, and dielectric space 417 pliable in cold weather conditions. It isa goal to have the weather seal properties maintained to applicationcompliance standards while heated. Additionally, the heated weather sealcould be used to prevent the window or sliding panel from freezingand/or to aid in thawing a frozen window or sliding panel while in theclosed position. Conductive fabric 414 would be engaged as a heatingelement when powered by relays turned on by controller 14 with inputsfrom a temperature sensor, which could be from the vehicle outsidetemperature sensor. The temperature input could also originate from aseparate temperature sensor located on a device inside the vehicle door,or anywhere else outside the vehicle.

The temperature setting to turn on conductive fabric 414 heating elementis optional, but would likely be set for temperatures at or below 40° F.where cold weather pliability is required. When the set temperature isreached, controller 14 turns conductive fabric 414 heater element on tomake the weather seal pliable. The circuit in controller 14 can also beconfigured to automatically cycle the conductive fabric 414 heaterelement on and off after the desired pliability is achieved tothereafter maintain pliability. By using relays or transistors theheater element can be powered such that an appropriate amount of currentflows through the element. The current flow through the resistiveelement will produce the required amount of heat following the wellknown equation Power (Watts)=I²×R. The power can be applied for a givenamount of time and then removed. During the time power is removed, theheating element can be connected to a circuit that provides a smallamount of current flow through the element and through a seriesconnected resistor.

Heating element 414 and the series connected resistor form a voltagedivider. The voltage that is developed can then be interpreted by amicroprocessor, or other device such as an op-amp, to determine thetemperature of the heating element. If the temperature is below adetermined set-point, heating element 414 can again be connected suchthat power is applied to it increasing the amount of heat generated.After the temperature sensor determines that the temperature is abovethe set point, controller 14 turns off the relays providing power toconductive fabric 414 heater element.

Alternatively, controller 14 can be configured to inhibit a user inputcommand to open a window or sliding panel when, anytime during the timeof heating conductive fabric 414, no window or panel movement is sensed,indicating a stalled motor condition such as may be caused by ice buildup in the weather seal. During such an event, controller 14 continues toinhibit user commands to open the window or sliding panel untilconductive fabric 414 heater element inside the weather seal hasachieved a temperature sufficient to free the window or sliding panel.Controller 14 could be configured to recognize the above condition fromtemperature sensor inputs at all times, including when vehicle ignitionand/or other vehicle power is off. Implementation of this function couldreduce warranty costs related to the window or sliding panel drivemechanism, seals, and motor.

Alternatively, conductive fabric 414 could be used as a heating elementinside a weather seal not using an anti-pinch strip system. In thiscase, controller 14 is configured to only control the heating elementfunction as described above. The controlling function could also beintegrated as part of other electronics being employed within theapplication system.

Alternatively, conductive fabric 414 could be used as a temperaturesensor, either as a stand alone sensor, or in combination with theanti-pinch system. The function to switch between temperature sensingand anti-pinch sensing would be configured through controller 14. Thetemperature sensing function of conductive fabric 414 could be used toprovide the same temperature inputs required to operate the anti-pinchsystem as described above.

Referring now to FIGS. 48 and 49, a sensor 418 in accordance with a15^(th) sensor embodiment is shown. In general, sensor 418 is acombination proximity/displacement sensor with conductive fabricattached to an inside profile. The conductive fabric can be used as aheating element and temperature sensor. When pressure is applied to anon-conductive elastomer outer jacket 419, which can be covered withflexible non-conductive flocking material 421, space 423, compresses tomove a first conductive fabric 420, attached internally toanon-conductive outer jacket 413, towards a second conductive fabric422. To this end, space 423 can be air, foam, or any dielectric materialformulated to allow for low force.

Sensor 418 registers a change in capacitance whenever the distancebetween first conductive fabric 420 and second conductive fabric 422changes as a result of an object touching non-conductive flockingmaterial covering 421 and/or as a result of an electrically conductiveobject coming into proximity with first conductive fabric 420. Thechange in capacitance is signaled to controller 14.

Conductive fabric 420 may be used as a heating element when theanti-pinch strip system is inactive. The heating element function can beused to heat sensor 418, which may be being used as a weather seal,keeping elastomer outer jacket 419, non-conductive flocking material421, and dielectric space 423 pliable in cold weather conditions. It isa goal to have the weather seal properties maintained to applicationcompliance standards while heated. Additionally, the heated weather sealcould be used to prevent the window or sliding panel from freezingand/or to aid in thawing a frozen window or sliding panel while in theclosed position. Conductive fabric 420 would be engaged as a heatingelement when powered by relays turned on by controller 14 with inputsfrom a temperature sensor, which could be from the vehicle outsidetemperature sensor. The temperature input could also originate from aseparate temperature sensor located on a device inside the vehicle door,or anywhere else outside the vehicle.

The temperature setting to turn on the conductive fabric 420 heatingelement is optional, but would likely be set for temperatures at orbelow 40° F. where cold weather pliability is required. When the settemperature is reached, controller 14 turns conductive fabric 420 heaterelement on to make the weather seal pliable. The circuit in controller14 can also be configured to automatically cycle the conductive fabric420 heater element on and off after the desired pliability is achievedto thereafter maintain pliability. By using relays or transistors theheater element can be powered such that an appropriate amount of currentflows through the element. The current flow through the resistiveelement will produce the required amount of heat following the wellknown equation Power (Watts)=I²×R. The power can be applied for a givenamount of time and then removed. During the time power is removed, theheating element can be connected to a circuit that provides a smallamount of current flow through the element and through a seriesconnected resistor.

The heating element 420 and the series connected resistor form a voltagedivider. The voltage that is developed can then be interpreted by amicroprocessor, or other device such as an op-amp, to determine thetemperature of the heating element. If the temperature is below adetermined set-point, heating element 420 can again be connected suchthat power is applied to it increasing the amount of heat generated.After the temperature sensor determines that the temperature is abovethe set point, controller 14 turns off the relays providing power toconductive fabric 420 heater element.

Alternatively, controller 14 can be configured to inhibit a user inputcommand to open a window or sliding panel when, anytime during the timeof heating conductive fabric 420, no window or panel movement is sensed,indicating a stalled motor condition such as may be caused by ice buildup in the weather seal. During such an event, controller 14 continues toinhibit user commands to open the window or sliding panel untilconductive fabric 420 heater element inside the weather seal hasachieved a temperature sufficient to free the window or sliding panel.Controller 14 could be configured to recognize the above condition fromtemperature sensor inputs at all times, including when vehicle ignitionand/or other vehicle power is off. Implementation of this function couldreduce warranty costs related to the window or sliding panel drivemechanism, seals, and motor.

Alternatively, conductive fabric 420 could be used as a heating elementinside a weather seal not using an anti-pinch strip system. In thiscase, controller 14 is configured to only control the heating elementfunction as described above. The controlling function could also beintegrated as part of other electronics being employed within theapplication system.

Alternatively, conductive fabric 420 could be used as a temperaturesensor, either as a stand alone sensor, or in combination with theanti-pinch system. The function to switch between temperature sensingand anti-pinch sensing would be configured through controller 14. Thetemperature sensing function of conductive fabric 420 could be used toprovide the same temperature inputs required to operate the anti-pinchsystem as described above.

Referring now to FIGS. 50 and 51, a sensor 424 in accordance with a16^(th) sensor embodiment is shown. In general, sensor 424 includes aconductive fabric attached to an outside profile for use as heatingelement and temperature sensor. Sensor 424 further uses a conductivefabric inside the profile for use as a proximity/displacement sensor.When pressure is applied to a non-conductive elastomer outer jacket 425,space 430, compresses to move a first conductive fabric 426, attachedinternally to a non-conductive outer jacket 425, towards a secondconductive fabric 427. To this end, space 430 is an air, foam, or anydielectric material formulated to allow for low force.

Sensor 424 registers a change in capacitance whenever the distancebetween first conductive fabric 426 and second conductive fabric 427changes as a result of an object touching non-conductive flockingmaterial covering 429 and/or as a result of an electrically conductiveobject coming into proximity with first conductive fabric 426. Thechange in capacitance is signaled to controller 14. A conductive fabric428, attached externally to a non-conductive elastomer outer jacket 425and covered with a flexible non-conductive flocking material 429, isused a heating element.

The heating element function can be used to heat sensor 424, which maybe being used as a weather seal, keeping elastomer outer jacket 425,non-conductive flocking material 429, and dielectric space 430 pliablein cold weather conditions. It is a goal to have the weather sealproperties maintained to application compliance standards while heated.Additionally, the heated weather seal could be used to prevent thewindow or sliding panel from freezing and/or to aid in thawing a frozenwindow or sliding panel while in the closed position. Conductive fabric428 heating element would be powered by relays turned on by controller14, either manually or with inputs from a temperature sensor, whichcould be from the vehicle outside temperature sensor. The temperatureinput could also originate from a separate temperature sensor located ona device inside the vehicle door, or anywhere else outside the vehicle.The temperature setting to turn on conductive fabric 428 heating elementis optional, but would likely be set for temperatures at or below 40° F.where cold weather pliability is required.

When the set temperature is reached, controller 14 turns conductivefabric 428 heater element on to make the weather seal pliable. Thecircuit in controller 14 can also be configured to automatically cycleconductive fabric 428 heater element on and off after the desiredpliability is achieved to thereafter maintain pliability. By usingrelays or transistors the heater element can be powered such that anappropriate amount of current flows through the element. The currentflow through the resistive element 428 produces the required amount ofheat following the well known equation Power (Watts)=I²×R. The power canbe applied for a given amount of time and then removed. During the timepower is removed, the heating element can be connected to a circuit thatprovides a small amount of current flow through the element and througha series connected resistor.

Heating element 428 and the series connected resistor form a voltagedivider. The voltage that is developed can then be interpreted by amicroprocessor, or other device such as an op-amp, to determine thetemperature of heating element 428. If the temperature is below adetermined set-point, heating element 428 can again be connected suchthat power is applied to it increasing the amount of heat generated.After the temperature sensor determines that the temperature is abovethe set point, controller 14 turns off the relays providing power toconductive fabric 428 heater element.

Alternatively, controller 14 can be used to inhibit a user input commandto open a window or sliding panel when, anytime during the time ofheating conductive fabric 428, no window or panel movement is sensed,indicating a stalled motor condition such as may be caused by ice buildup in the weather seal. During such an event, controller 14 continues toinhibit user commands to open the window or sliding panel untilconductive fabric 428 heater element inside the weather seal hasachieved a temperature sufficient to free the window or sliding panel.Controller 14 could be configured to recognize the above condition fromtemperature sensor inputs at all times, including when vehicle ignitionand/or other vehicle power is off. Implementation of this function couldreduce warranty costs related to the window or sliding panel drivemechanism, seals, and motor.

Alternatively, conductive fabric 428 can be used as a heating element ona weather seal not using an anti-pinch strip system. In this case,controller 14 is configured to only control the heating element functionas described above. The controlling function could also be integrated aspart of other electronics being employed within the application system.

Alternatively, conductive fabric 428 could be used as a temperaturesensor, either as a stand alone sensor, or in combination with theheating element function. The function to switch between temperaturesensing and heating would be configured through controller 14. Thetemperature sensing function of conductive fabric 428 could be used toprovide the same temperature inputs required to operate the anti-pinchsystem as described above.

Referring now to FIGS. 52 and 53, a sensor 431 in accordance with a17^(th) sensor embodiment is shown. In a preferred embodiment, ananti-pinch sensor strip, which could be in the form of a weather seal,is affixed to a non-moving member. In this preferred embodiment, awindow or sliding panel moves toward or away from the fixed anti-pinchsensor strip. In FIGS. 52 and 53, sensor 431 is configured to be part ofthe window or sliding panel. In general, sensor 431 is a proximitysensor with conductive elements located on a rigid moving member. Theconductive elements can also be used as heating elements.

Sensor 431 registers a change in capacitance as a result of anelectrically conductive object coming into proximity with leading edgeof window or sliding panel 432. The change in capacitance is signaled tocontroller 14. As shown in FIG. 53, a first conductive strip 433 and asecond conductive strip 434, which could be composed of indium tinoxide, copper or other conductive materials, are deposited to eitherside of window or sliding panel 432 in close proximity to the leadingedge. Conductive strips 433 and 434 continuously follow the leading edgeof window or sliding panel 432 wherever pinching may occur duringclosure. Electrical connection between conductive strips 433 and 434 andcontroller 14 could be made by wire cable interface, or RF signal. In anRF configuration, battery powered electronics attached to the window orsliding panel could provide the necessary sensor information forobstruction detection and motor control.

In the case of controller 14 receiving sensor signals responsive tomotor 18 or other moving members, the controller would have additionalanti-entrapment capabilities by making use of motor current and/orcommutator pulses and/or sensor signals from Hall (or other type)sensors. This would have the added benefit of being able to detectobstructions while the moving member and the obstruction are too faraway from sensor 431 to be sensed by sensor 431, or the obstruction is anon electrically conducting member.

Alternatively, conductive strips 433 and 434 can be used as a heatingelement when the anti-pinch strip system is inactive. It is a to use theheated portion of the window or sliding panel to aid in keeping theweather seal properties maintained to application compliance standardswhile heated. Additionally, the heated leading edge of window or slidingpanel 432 could be used to prevent freezing and/or to aid in thawing afrozen window or sliding panel while in the closed position. Conductivestrips 433 and 434 would be engaged as a heating element when powered byrelays turned on by electronic controller 14 with inputs from atemperature sensor, which could be from the vehicle outside temperaturesensor. The temperature input could also originate from a separatetemperature sensor located on a device inside the vehicle door, oranywhere else outside the vehicle. The temperature setting to turn onconductive strips 433 and 434 as a heating element is optional, butwould likely be set for temperatures at or below 40° F. where coldweather pliability is required.

When the set temperature is reached, controller 14 turns conductivestrips 433 and 434 as a heater element on to make the weather sealpliable. The circuit in controller 14 can also be configured toautomatically cycle conductive strips 433 and 434 as a heater element onand off after the desired pliability of the mating weather seal isachieved to thereafter maintain pliability. By using relays ortransistors the heater element can be powered such that an appropriateamount of current flows through the element. The current flow throughthe resistive element will produce the required amount of heat followingthe well known equation Power (Watts)=I²×R. The power can be applied fora given amount of time and then removed. During the time power isremoved; heating element 433 and 434 can be connected to a circuit thatprovides a small amount of current flow through the element and througha series connected resistor.

Heating element 433 and 434 and the series connected resistor form avoltage divider. The voltage that is developed can then be interpretedby a microprocessor, or other device such as an op-amp, to determine thetemperature of the heating element. If the temperature is below adetermined set-point, the heating element can again be connected suchthat power is applied to it increasing the amount of heat generated.After the temperature sensor determines that the temperature is abovethe set point, controller 14 turns off the relays providing power toconductive strips 433 and 434 heater element. For efficiency, controller14 could also be configured to inhibit the heater element function whenthe window or sliding panel is not in the closed position.

Alternatively, controller 14 can be used to inhibit a user input commandto open a window or sliding panel when, anytime during the time ofheating conductive strips 433 and 434, no window or panel movement issensed, indicating a stalled motor condition such as may be caused byice build up in the weather seal. During such an event, controller 14continues to inhibit user commands to open the window or sliding paneluntil conductive strips 433 and 434 heater element has achieved atemperature sufficient to free the window or sliding panel. Controller14 could be configured to recognize the above condition from temperaturesensor inputs at all times, including when vehicle ignition and/or othervehicle power is off. Implementation of this function could reducewarranty costs related to the window or sliding panel drive mechanism,seals, and motor.

Alternatively, conductive strips 433 and 434 can be used as a heatingelement on a window or sliding panel not using an anti-pinch stripsystem. In this case, controller 14 is configured to only control theheating element function as described above. The controlling functioncould also be integrated as part of other electronics being employedwithin the application system.

Referring now to FIGS. 54 and 55, cross-sectional views of a sensor 449and a sensor 470 in accordance with 18^(th) and 19^(th) sensorembodiments are respectively shown. Sensor 449 is configured with adielectric space 452 which preferably has a thickness of 0.75 mm. Firstand second conductor plates (i.e., flat wires) 450, 451 sandwichdielectric space 452. Dielectric space 452 is filled with a dielectricmedium 452 a such as a dielectric compressible elastomer. An elastomerouter jacket 457 encases conductor plates 450, 451 and dielectric medium452 a. Elastomer outer jacket 457 has angled side walls 455. Angled sidewalls 455 of outer jacket 457 function as a dovetailing feature forattaching sensor 449 to an automotive window weather seal, or other suchapplications.

Sensor 470 is generally similar to sensor 449 but differs in thatdielectric space 452 preferably has a thickness of 1.5 mm and outerjacket 457 has straight side walls. Sensor 470 is attachable by means ofadhesive products, or over molding into a weather seal or other end useapplication.

Conductor plates 450, 451 of sensors 449 and 470 are respectivelyequivalent to conductors 22, 24 of sensor 12 shown in FIG. 2 and arealso respectively equivalent to first and second flexible conductivemetal wires 302, 304 of sensor 300 shown in FIGS. 34 and 35.

Dielectric space 452 of sensors 449 and 470, which is filled withdielectric medium 452 a, maintains a predefined distance betweenconductor plates 450, 451. Optimally, the predefined distance is 1.5 mmsuch as shown in FIG. 55, but can be changed as required for aparticular application. Dielectric medium 452 a can have eithercompressible or non-compressible capabilities. Conductor plates 450, 451are similar in function to conductors 302, 304 of sensor 300 shown inFIGS. 34 and 35 and provide pinch and proximity sensor signals 21, 23 tocontroller 14.

The capacitances of sensors 449, 470 changes as a result of an object inproximity to the sensor or as a result of physical contact with thesensor which causes conductor plates 450, 451 to move closer together orwhich otherwise alters the relative orientation of the conductor plateswith respect to one another. That is, the sensor capacitance changes asconductor plates 450, 451 become closer together.

As shown in FIG. 58, the signal strength of sensor 449 (and sensor 470)increases as the proximity of an object to the sensor increases (i.e.,as the proximity of an object to at least one of the conductor plates450, 451 increases). Also, as conductor plates 450, 451 become longer,dielectric space 452 provided between the conductor plates is optimizedto provide the maximum signal. A material thickness 456 of 0.13 mm forconductor plates 450, 451 allows cost effective manufacturing, yet isdurable enough to allow repeated flexure of conductor plates 450, 451without fatiguing or fracturing.

The preferred material for conductor plates 450, 451 is spring temperalloy 510 phosphor bronze, but could be any electrically conductivematerial, such as tempered steel, tin coated to prevent oxidation or aconductive film printed on a flexible substrate. Phosphor bronze alsohas inherent properties making it ideal for solder or other attachmentof connector wires.

Sensors 449, 470 are shown in FIGS. 54 and 55 in the optimal packagesize to provide both proximity and pinch sensor signals. For sensing anobstruction with either pinch or proximity signals, the optimal width453 of conductor plates 450, 451 falls within the range of 6 mm to 7 mmand preferably is either 6.35 mm or 6.7 mm.

As shown in FIG. 56, conductor plates 450, 451 of sensor 449 (and sensor470) are constructed in a serpentine pattern with spaced slots 461. Thisconfiguration provides flexibility for conforming sensors 449, 470 toshapes that would apply a load perpendicularly to the flat planarsurface of conductor plates 450, 451 in certain applications. The spacedslots 461 are preferably 0.5 mm wide and 5 mm in length, spaced 2.5 mmapart along the entire length of conductor plates 450, 451. Other slotsizes, spacings, and patterns could be used to accomplish the sameflexibility purpose specific to a given application of sensors 449, 470.

By increasing the widths 453 of conductor plates 450, 451, a largeroverall sensor can be created to allow for a greater surface area ofentrapment protection. As shown in FIG. 59, testing has established thatas conductor plates 450, 451 become wider, the capacitance signalstrength increases. The signal strength is also affected by the materialused for conductor plates 450, 451 as shown in FIG. 59.

Sensors 449, 470 are sized for a typical automobile door window sealapplication, and have a minimum profile designed to not reduce viewingthrough the window opening. As shown in FIG. 57, sensor 449 is attachedto a weather seal 459. Weather seal 459 is attached to an automobilewindow frame 460. Frame 460 and weather seal 459 have an opening forreceiving an automobile window 458 when the window is in a fully closedposition.

If a non-compressible material is used, then sensors 449, 470 provideproximity sensing only operation. If compressible material is used, thensensors 449, 470 provide both pinch and proximity sensing operations. Apreferred material for dielectric medium 452 a of sensors 449, 470 is anelectrically non-conductive flexible polyurethane foam, such as RogersCorporation Poron 4701-30-20062-04. Other foam materials, such as EPDM,thermoplastic rubber, thermoplastic elastomer, or TPV could also be usedfor dielectric medium 452 a. These materials are currently used inwindow seals to meet the appearance and reliability requirements forwindow closures. Santoprene, a thermoplastic elastomer material made byAdvanced Elastomer Systems, maintains stable compression characteristicsover temperature, whereas EPDM compression characteristics decrease astemperature is reduced.

Stiff compression characteristics increase pinch forces. A material,which maintains flexibility and compression characteristics when cold,is preferred for pinch operation of sensors 449, 470. The material fordielectric medium 452 a could be introduced by co-extrusion as any ofthe materials mentioned, or made by foaming the outer jacket 457material in dielectric space 452 between conductor plates 450, 451. Afoamed space 452 would be made up of the material of outer jacket 457and air as the dielectric.

A preferred material of outer jacket 457 is a non-electricallyconductive thermoplastic rubber or elastomer material, such asSantoprene. The surface resistivity of outer jacket 457 and dielectricmedium 452 a is to be set greater than 10⁶ ohm/cm to avoid electricalshorting potential between conductor plates 450, 451. The thickness 454of the material of outer jacket 457 between conductor plate 450 and thesensing surface of the outer jacket contains the optimal outer jacketmaterial thickness required to (a) completely enclose conductor plates450, 451 and dielectric medium 452 a (i.e., completely enclose sensors449, 470) with outer jacket 457 to prevent moisture infiltration; (b)reduce the possibility of voids; and (c) keep the dimension betweenconductor plates 450, 451 at a useful spacing to provide usefulproximity mode detection and sensitivity.

As previously described, in the test results shown in FIG. 59, for therange of distances shown, as outer jacket thickness 454 increases theproximity detection capability of controller 14 is reduced. As width 453of conductor plates 450, 451 increases, the discrimination ability ofsensors 449, 470 improves as less amplification of the signal isrequired. This provides more stability and greater sensing distancesbetween object 16 and sensors 449, 470.

Referring now to FIG. 60, a perspective view of a capacitance sensor 600in accordance with a preferred embodiment is shown. Sensor 600 includesa top flexible conductor 602, a compressible dielectric or air filledvolume 604, and a bottom flexible conductor 603. Top and bottomconductors 602, 603 have a generally thin ribbon form factor. Dielectricvolume 604 is generally in a strip form factor interposed betweenconductors 602, 603 and separates the conductors by a distance 606.Distance 606 may be constant or may vary along the length of sensor 600.Conductor ribbons 602, 603 have respective widths 601, 605. Widths 601,605 may be constant or may vary along the length of sensor 600. Sensor600 itself can be bent in directions transverse to its longitudinal axisor be twisted around its longitudinal axis. As will now be describedbelow, sensor 600 will behave approximately as a parallel platecapacitor.

Referring now to FIGS. 61 a and 61 b, with continual reference to FIG.60, sensor 600 behaving as a parallel plate capacitor is shown. FIGS. 61a and 61 b respectively illustrate a cross-sectional view of sensor 600and an angled side view of the sensor behaving as a parallel platecapacitor.

Like sensor 600, a parallel plate capacitor includes two conductiveplates 602, 603 separated by a volume 604 which is filled with eitherspace or a dielectric medium having permittivity ε. As long as the ratioof sensor width 605 (denoted as “w”) to sensor height 606 (denoted as“h”) (i.e., width to height ratio=w/h) and the ratio of sensor length607 (denoted as “L”) to sensor height 606 (i.e., length to heightratio=L/h) are both five or larger, then fringe effects can be largelyignored. The capacitance “C” of sensor 600 is then approximately:C=(ε*w*L)/h  (1)

The charge “Q” that sensor 600 can hold when a voltage “V” is applied isthen approximately:Q=C*V  (2)

From expressions (1) and (2) it follows that capacitance (C) and thecharge (Q) on sensor 600 varies directly with its width (w), length (L)and permittivity (ε) and varies inversely with its height (h). As aresult, any phenomenon that changes one of these parameters will resultin sensor 600 physically changing as well as the charge (Q) that thesensor can hold. Upon either one of the ratios (w/h) or (L/h) droppingbelow five, then fringe effects begin to become a factor as well.

For h and w dimensions on the order of 10 mm or less, aspect ratios of ¼to ½ and permittivities up to seven times that of free space (i.e.,ε≦7ε₀), the capacitance (C) of sensor 600 is approximately:C=(w*L)*[((a*ε ₀)+ε)/h]  (3)where a=1.071*(w/h)⁻⁰⁸⁷⁵

It is noted that expression (3) was semi-empirically derived using basicelectrostatic theory in conjunction with selected finite elementanalysis. For the parameter ranges given, the expression (3) predictscapacitance to within 2% of those obtained from finite element analysis.

Referring now to FIGS. 62 a and 62 b, with continual reference to FIGS.60, 61 a, and 61 b, sensor 600 operating in different sensing modes isshown. Sensor 600 has at least three sensing modes available for sensingentrapment when the sensor is located within or adjacent to an openingthat is being closed by a hinged or sliding panel or by a contractingiris and the like.

As shown in FIG. 62 a, in a first sensing mode a conductive object 608is capacitively coupled to ground and comes into close proximity withsensor 600. If top conductive plate 602 is set at a non-zero voltagewith respect to bottom conductive plate 603 when the bottom conductiveplate is grounded, then conductive object 608 will in-turn capacitivelycouple to sensor 600 when the object comes within sufficient proximityto the sensor. The result is that the capacitively grounded conductiveobject 608 will appear as another capacitance to ground in parallel withsensor 600. This will make sensor 600 appear to have a largercapacitance. If conductive object 608 is conductively grounded, thensensor 600 will appear to have a larger capacitance as the objectapproaches and capacitively couples to the sensor as long as the objectdoes not make conductive contact with top conductive plate 602.

FIG. 63 illustrates an equivalent circuit for the sensor arrangementshown in FIG. 62A. In FIG. 63, the capacitance of object 608 withrespect to ground is given by “Co”, the coupling capacitance between theobject and sensor 600 is given by “Cc”, and the capacitance of thesensor is given by “Cs”. Top conductor 602 of sensor 600 is tied to V+and bottom conductor 603 is tied to ground.

Applying circuit laws to this equivalent circuit as follows:C _(apparent) =Cs+[(1)/[(1/Cc)+(1/Co)]]  (4)simplify

[(Cs*Co)+(Cs*Cc)+(Cc*Co)]/[(Co+Cc)]then C_(apparent)=240 pF (when Cs=200 pF, Cc=50 pF, Co=200 pF).

As such, a 200 pF sensor coupled to an object with a 200 pF capacitivecoupling to ground via a 50 pF coupling capacitance results in anapparent sensor capacitance of 240 pF. This shows that the capacitanceof sensor 600 appears to increase when a capacitively or conductivelygrounded object comes close enough to the sensor to capacitively coupleto the sensor. In the case of a conductively grounded conductive objectthe capacitance Co of the object is replaced by a resistance. Then aslong as the voltage of sensor 600 is allowed to settle for longer thanthe time constant of the coupling capacitor and the object resistance,the affect will be to increase the apparent capacitance of sensor 600 byCc.

As shown in FIG. 62 b, in another sensing mode a non-conductive object608 is seen to impinge on sensor 600 sufficiently to cause compressionof dielectric 604. The compression of dielectric 604 results in adecrease in height 606 between top and bottom conductors 602, 603 in theregion of non-conductive object 608. From simple electrostatic theory,in the arrangement shown in FIG. 62 b, sensor 600 could be considered asthree smaller capacitors connected in parallel and segmented as shown bysegment boundaries 609.

In this way, the region with compression could be treated as a separatecapacitor connected in parallel to capacitors formed by the uncompressedregions to either side of the compressed region. Referring to theexpression (3), a decrease in h in the compressed region increases thecapacitance in that region of sensor 600 resulting in an overallincrease in capacitance in the sensor. Ignoring fringe effects, a sensor600 having a length of 1.4 m length, a width of 6 mm, a height of 1.6mm, and a permittivity ε=3ε₀ will have a capacitance of 131 pF. If a 2cm long region is then uniformly compressed to a thickness of 0.25 mm,then the capacitance of this sensor will increase to 142 pF.

Still referring to FIG. 62 b, if non-conductive object 608 makes contactwith sensor 600 in such a manner as to change the conductance of thesensor or the permittivity of the sensor, the capacitance of the sensorthen changes according to the expression (3). Among other possibilities,non-conductive object 608 could modify conductance or permittivitythrough applying pressure, heat, or a magnetic field.

All three of these sensing modes can be employed with sensor 600 in itsconstruction shown in FIG. 60. However, depending on the degree ofbending and twisting in sensor 600, the capacitance of the sensor can beexpected to depart to some degree from that predicted by the expression(3).

As described with reference to FIG. 60, the basic elements of capacitivesensor 600 in accordance with a preferred embodiment include a flexibletop conductor 602, a bottom conductor 603, and a non-conductivedielectric or air-filled volume 604 interposed between the twoconductors. Top and bottom conductors 602, 603 are generally in a thinribbon form factor and dielectric volume 604 is generally in a stripform factor interposed between the two conductors. Dielectric volume 604separates the two conductors 602, 603 by a distance 606 which could veryalong the length of the sensor. Conductor ribbons 602, 603 haverespective widths 605, 606 that could also very along the length ofsensor 600. To facilitate installation adjacent to or in the closureregion of a closing mechanism such as a door or window, sensor 600itself can be bent in directions transverse to its longitudinal axis orbe twisted around its longitudinal axis. Subsequent to mounting, theresponse of sensor 600 to imposed variations in width, height, length,and permittivity will approximate the response to the imposed variationsthat would be seen in a similarly sized parallel plate capacitor.

As long as the ratio of width 605 to height 606 and the ratio of length607 to height are both at least five, bending radii are large withrespect to the height, and the length and the amount of twisting issmall in lengths along sensor 600 comparable to the width or the height,then fringe effects can be largely ignored and the capacitance (C) willbe approximately given by the expression (1):C=(ε*w*L)/h  (1)

The charge (Q) that sensor 600 can hold when a voltage is applied isthen given by the expression (2):Q=C*V  (2)

From the expressions (1) and (2), it follows that the capacitance (C)and the charge (Q) on sensor 600 (see FIGS. 61 a, 61 b) will varydirectly with the width, length, permittivity of the sensor and willvary inversely with the height of the capacitor. As a result, anyphenomenon that changes one of these parameters will result in sensor600 changing and will result in the charge (Q) that the sensor can holdchanging as well. Upon either of the two ratios (w/h) or (L/h) droppingbelow five, then fringe effects begin to become a factor as well. Forheight and width dimension on the order of 10 mm or less, aspect ratiosof ¼ to ½, and permittivities up to seven times that of free space(i.e., ε≦7ε₀), the capacitance (C) of sensor 600 is approximately givenby expression (3):C=(w*L)*[((a*ε ₀)+ε)/h]  (3)where a=1.071*(w/h)^(−0.875)

Again, it is noted that expression (3) was semi-empirically derivedusing basic electrostatic theory in conjunction with selected finiteelement analysis. For the parameter ranges given, the expression (3)predicts capacitance to within 2% of those obtained from finite elementanalysis. For short radius bending of sensor 600 or for extreme twistingof the sensor about its longitudinal axis, significant departure fromthe absolute predictions of the expression (3) can be expected. However,the proportional response to changes in height (h), width (w), andlength (L) can still be expected to generally follow that indicated bythe expression (3) once a set of bends or twists have been made inaccomplishing a sensor installation provided that the sensor does notundergo further twists or bends.

Changes in capacitance (C) due to twisting or bending of sensor 600 inresponse to the touch of an object 608 can be used to sense the presenceof the object. However, the specific response that can be expected canbe more difficult to determine theoretically and in a practicalapplication would preferably be determined empirically on an“application by application” basis.

Thus, as described, sensor 600 has at least three available sensingmodes. These three available sensing modes are: (i) proximity sensing ofconductive objects 608, (ii) contact sensing of an object whose contactcauses compression of sensor 600 thereby reducing the height in at leastone region along the sensor, and (iii) contact sensing of an object 608that causes changes in conductivity or permittivity in at least oneregion along the sensor. A fourth sensing mode as described above arisesfrom contact sensing of an object 608 that causes bending or twisting ofsensor 600.

Summarizing contact sensing, any contact with sensor 600 that causesdeformation of the sensor or a change in its dielectric or conductiveproperties may result in a detectable change in the sensor signal outputthat can be used as an indication of contact with an object 608. Thatindication or the indication from a proximity detection of a conductiveobject 608 can then be provided to a controller for the closing device(such as a window) so that the controller can alter operation of theclosing device so as to prevent or reverse an entrapment of the object.

Referring now to FIG. 64, a useful variation of sensor 600 is shown. Inthis variation, top and/or bottom conductors 602, 603 of sensor 600 is ametallic strip formed into a serpentine pattern. This allows sensor 600to be subjected to greater degrees of bending and twisting atinstallation with a smaller effect on the capacitance of the sensor thanis seen with the sensor constructed with a solid metallic ribbon ofcomparable thickness and material. This arises from the fact that theserpentine pattern generally has a lower width to bend radius ratio forbends and twists than will a sensor with a solid strip conductor forcomparable bends and twists. As a result, for bends and twists atinstallation, the serpentine pattern results in less compression anddeformation of dielectric volume 604 between conductors 602, 603 than isseen when solid strip conductors are used. A further advantage arises inthat with less deformation of dielectric volume 604 between conductors602, 603, the mechanical stiffness will be reduced allowing sensor 600to remain more deformable and therefore more sensitive in response tothe touch of an object that comes into contact with the sensor.

In an alternative approach, thin conductive films can be applieddirectly to the top and bottom of dielectric volume 604 betweenconductors 602, 603. For instance, dielectric volume 604 could be filledwith closed cell foam and conductors 602, 603 could be a conductivepaint or conductive film plated or adhered to the top and/or bottom ofthe closed cell foam. This offers the advantage of lowering part countand simplifying assembly of sensor 600. It also enhances thedeformability of sensor 600 if a soft foam is used while otherwisemaintaining the relative orientations of conductors 602, 603 withrespect to each other.

Referring now to FIGS. 65 a, 65 b, and 65 c, a further variation ofsensor 600 is shown. In FIGS. 65 a and 65 b, top conductor 602 is seento be narrower than bottom conductor 603. Further, top conductor 602 istaken to a non-zero potential (V+) and lower conductor 603 is grounded.This contrasts to the nominal configuration shown in FIG. 65 c where topand bottom conductors 602, 603 have comparable widths.

Contrasting the two configurations of FIGS. 65 a and 65 c, acapacitively grounded conductive object 608 coming in proximity to theside of 600 sensor, but not passing directly overhead of the sensor,induces a smaller proportionate change in apparent capacitance in thesensor for the configuration of FIG. 65 a than that for theconfiguration of FIG. 65 c. That is, the configuration of FIG. 65 a hasa more directional response. This is due to the fact that the widergrounded conductor 603 operates in part as a partial shield with respectto objects laterally displaced from sensor 600. This can offer asignificant advantage in cases where proximity sensing is desirable onlywhen a conductive object 608 is directly over as opposed to diagonallyoverhead sensor 600. A further advantage is that the configuration ofFIG. 65 a is less responsive than that of the configuration of FIG. 65 cfor capacitively grounded objects directly to the side of or belowsensor 600. If on the other hand, a less directional response than thatof the configuration of FIG. 65 a or 65 c is desired, top conductor 602can be made wider than bottom conductor 603 resulting in an enhancedresponse to objects that are not directly above sensor 600 where itwould tend to be maximally sensitive anyway.

A further enhancement in operating modes can be realized inconfigurations of either FIG. 65 a or 65 c by actively interchanging theroles of top and bottom conductors 602, 603 in terms of how voltagepotential and ground are applied to sensor 600. In the case where itwould be desirable to distinguish between whether or not objectdetection has occurred via proximity sensing vs. contact sensing, theelectrical polarity to sensor 600 could be reversed resulting in topconductor 602 becoming ground and lower conductor 603 becoming V+,resulting in the sensor then having a smaller response to capacitivelygrounded conductive objects 608 directly or diagonally above it. Whereasfor a contact sensed object, little or no change in sensor responsecould be expected assuming there is no significant change in capacitivecoupling to structures to which sensor 600 is mounted.

An additional enhancement is possible in cases where there would besignificant capacitive coupling to underlying structures upon whichsensor 600 is mounted. In this enhanced configuration a third conductor(i.e., a third conductive layer) is interposed between the structure towhich the sensor is mounted and sensor 600. A first insulating layer orgap is interposed between the structure and the third conductive layer.A second insulating layer or gap is interposed between the thirdconductive layer and the conductor (602 or 603) which is closest to thestructure. This third conductive layer is grounded for normal operationto shield sensor 600 from coupling to the structure and is then taken toV+if sensor polarity is reversed so as to act as a “driven shield” toprevent capacitive coupling to the structure at reversed polarity.

Referring now to FIG. 66, a further variation of sensor 600 is shown. Inthe enhancement top or bottom conductor 602, 603 is segmented (topconductor 602 is segmented in FIG. 66). Non-conductive dielectric of airfilled volume element 604 may or may not be segmented as well. In thisenhancement the segmented top conductor 602 has means to apply voltageto each top conductor segment and means to obtain the signal due to thecapacitance of each top conductor segment independently. With thisconfiguration the number and/or pattern of elements indicating thepresence of an obstruction can be used to give an indication of the sizeof the obstruction and/or the force applied to it during contactsensing. In the case where all elements simultaneously indicate anobstruction, this could be used as an indicator of device closurewithout obstruction in the closing device to which sensor 600 is mountedwhere objects likely to be trapped are not sufficiently large or shapedso as to engage all sensor elements simultaneously.

Referring now to FIG. 67, a further variation of sensor 600 is shown. Inthis variation, the cross-section of sensor 600 is varied along itslength to pre-compensate for conditions that could adversely affect thesensor performance or signal level upon and/or after installation. Theseconditions may include, but are not limited to, bending and twisting ofsensor 600 at installation, nearby fixed objects that provide abackground coupling to the sensor and regions of the sensor that mightbe at a different temperature, subjected to a greater or lesser degreeof proximity to objects to be sensed or experience a greater or lesserdegree of compression from objects that are to be contact sensed.Variation of the cross-section in this manner effectively provides ameans to vary the sensitivity of sensor 600 along its length. Amongother advantages this offers the possibility of pre-compensating forchanges in sensor sensitivity in regions of bends and twists requiredfor installation. Further, by varying the width of bottom conductor 603independently of the width of top conductor 602 and/or locally alteringthe angle between the planes of conductors 602, 603 as shown in FIG. 68,the directional response of sensor 600 can be varied along its length tomask out or focus in on pre-selected directions and/or regions.

Referring now to FIG. 69, a further variation of sensor 600 is shown. Inthis variation the directional sensitivity of sensor 600 is furtheraugmented. In this variation, bottom conductor 603 is given a “channel”shape so as to partially surround top conductor 602. Top conductor 602may or may not have a “channel” shape. With bottom conductor 603grounded, this configuration of sensor 600 may provide an even moredirectional response than that in the preceding configurations. Bytwisting sensor 600 about it longitudinal axis this directional responsecan be steered along the length of the sensor to focus in on directionsand regions of interest. By turning sensor 600 upside down and reversingits polarity, the sensor can be configured to have a proximity responsein all but a small angular direction. This could be used to rendersensor 600 insensitive to certain features on the structure to which itis mounted or to make the sensor blind to the proximity of objects inlocations where entrapment of an obstruction would not be likely or ofconcern. For further directional sensitivity control the width and depthof the conductor channel or channels can be varied along the length ofsensor 600 as well as the amount of separation and relative locationbetween conductors 602, 603.

In another enhancement, one or more elements of sensor 600 are moldeddirectly into a seal or cushion of an opening that is being closed by ahinged or sliding panel. In this regard, FIG. 70 illustrates thecross-section of a weather seal 610 as well as the overall sensor 600.

In the configuration shown in FIG. 70, a malleable metallic conductor602 is incorporated within an extruded weather seal 610. Weather seal604 is composed of an elastomeric material such as a synthetic rubber.This offers advantages in terms of minimizing the construction andinstallation of sensor 600 as well as offering reliability advantagesthrough reduced part count and simplified assembly. Conductor 602 issufficiently thick and malleable to as to retain shapes into which it isbent or twisted along with weather seal 610. In this way weather seal610 can be pre-shaped so as to fit into a predetermined location in theboundary of a closing device such as an automotive window and therebysimplify and lower the cost of installation. Weather strip 610 mayfurther include a channel forming portion 609 to receive the edge of aclosing panel such as a window between the main body of the weatherstrip and the channel defining portion 609 so as to effect a betterweather sealing and provide greater system stability upon closure. A topportion 612 of weather seal 610 is formed so as to make a mating contactwith the boundary of the closing device.

Weather seal 610 further includes an air filled blister regioncontaining a second flexible conductor 603. The fixing of conductor 603within the blister and the flexibility of this conductor are tailored soas to enable a ready deformation of this conductor in response to thetouch of an object before an unacceptable amount of force is applied tothe object by the closing panel of the closing device. The blisterportion containing conductor 603 is further located so as to come intophysical contact with objects of concern such as human body parts thatcould become entrapped between the closing portion of the closing deviceand weather seal 610. The shape of conductors 602, 603 and the relativelocations and orientations of the conductors with respect to each otherare pre-selected and configured so as to enhance proximity detection ofconductive objects within the opening of the closing device before theybecome entrapped while minimizing the likelihood of undesirabledetections of conductive objects that are not in a location that islikely to result in entrapment such as a location beside but not withinthe opening that is being closed.

Referring now back to FIGS. 54 and 55, with continual reference to FIG.1, it is to be appreciated that sensors 449, 470 (which representpreferred embodiments of capacitance sensor 12 shown in FIG. 1 a) modela simple capacitor having two parallel conductive plates 450, 451separated by a dielectric layer 452. First conductor 450 is used forsensing the presence of a nearby object 16. First conductor 450accomplishes detection of object 16 by sensing the formation ofcapacitance between itself and the object as the object approaches thefirst conductor 450. Second conductor 451 is connected to ground andforms a shield or barrier that protects first conductor 450 from thecapacitive influence of objects positioned behind second conductor 451.Controller 14 reads the input sensor signal 23 indicative of thecapacitance between first conductor 450 and object 16 and this type ofdetection is referred to as proximity sensing.

Resulting from the direct proximity to one another, first and secondconductors 450, 451 create capacitance with each other. This capacitanceis on the order of 200 pF for a four foot length of sensors 449, 470.Sensors 449, 470 are optimized for sensing objects 16 that producecapacitance changes on the sensor on the order of 10% or greater. Assuch, sensors 449, 470 are suitable for detection of human body partssuch as fingers, hands, and the like. Second conductor 451 provides alow impedance electrical path back to the ground of controller 14. Assuch, the capacitance formed between conductors 450, 451 creates anatural input filter against electromagnetic interference.

When an application requires that sensors 449, 470 be remotely locatedfrom controller 14, a wire harness is used to complete electricalconnections between the sensor and the controller. This wire harness ispreferably a common type coaxial cable such as RG-174 having an innerconductor with an outer conductive shield. The inner conductor is usedto connect first conductor 450 to a sensor input signal pin ofcontroller 14. Connecting the outer conductive shield to the ground ofcontroller 14 provides stable capacitive loading along the length of theinner conductor and shields the inner conductor from external straycapacitance. The outer conductive shield of the harness then doubles asan electrical conductor making connection between the ground ofcontroller 14 and second conductor 451.

A characteristic of second conductor 451 is that it creates capacitancewith first conductor 450 significantly greater than the capacitance thatforms between the first conductor and a nearby object 16. The inclusionof a coaxial electrical harness in remote sensing applications furtherincreases this amount of capacitance. If an approaching object 16 isunable to establish a capacitance with first conductor 450 great enoughto be detected by controller 14, then the approaching object willeventually make contact with sensor 449, 470. The force generatedbetween object 16 and sensor 449, 470 causes first conductor 450 to movecloser to second conductor 451. The result of compression between firstand second conductors 450, 451 generates an increase of capacitance insensor 449, 470. This increased capacitance is measured by controller 14on sensor input signal 21 and this type of detection is referred to aspinch sensing.

Referring now to FIG. 71, with continual reference to FIGS. 1 a, 1 b,54, and 55, controller 14 of anti-entrapment system 10 is shown ingreater detail. In a preferred embodiment, controller 14 includes amicro-controller 507 which manages hardware operations and timing.Micro-controller 507 performs a number of software algorithms to detect,identify, and respond to objects 16 that approach sensor 12. In additionto sensing objects 16, controller 14 can accept external input commandsto operate motor 18 which in turn moves translating device 20.

When a voltage is applied across conductors 450, 451 of sensor 12, anelectrical charge develops in the sensor. The amount of electricalcharge developed is directly proportional to the unknown capacitance ofsensor 12. In order to measure input sensor signals 21, 23, controller14 uses a technique referred to as capacitive charge transfer.

To this end, micro-controller 507 closes a switch 503 which places aknown voltage 502 generated by a voltage source 501 across conductors450, 451 of sensor 12. This develops an electrical charge in sensor 12.After sensor 12 is fully charged, micro-controller 507 opens switch 503to isolate the sensor from voltage source 501. Next, micro-controller507 closes a switch 505 to transfer the electrical charge in sensor 12to a second charge storing capacitor 504. Upon completion of chargetransfer, micro-controller 507 then opens switch 505 again to isolatecharge storing capacitor 504 from sensor 12. A resulting charge left oncharge storing capacitor 504 produces a signal 513 indicative of thisresulting charge. Electronic stages 510, 509 of controller 14 conditionresulting charge signal 513 to produce a conditioned signal 508.

Micro-controller 507 measures conditioned signal 508. Signal 508represents sensor input signal 21, 23 from sensor 12. Oncemicro-controller 507 has acquired signal 508, micro-controller 507discharges charge storing capacitor 504 by closing switch 506. Afterdischarging charge storing capacitor 504, micro-controller 507 opensswitch 506 and another measurement sequence of sensor 12 is started.

The electrical charge developed in sensor 12 when known voltage 502 isapplied across its conductors 450, 451 is proportional to thecapacitance of the sensor. The capacitance of sensor 12 is determined byits physical characteristics. The two most important physicalcharacteristics being parallel surface area and separation distancebetween conductors 450, 451. When a conductive object 16 comes inproximity to sensor 12, a second capacitance between the object andfirst conductor 450 is created. Consequently, a second electrical chargedevelops between first conductor 450 and conductive object 16. The netelectrical charge stored on first conductor 450 is the sum of the twocharges. This new electrical charge results in a different voltagedeveloped on charge storing capacitor 504 during the charge transferprocess than is seen when conductive object 16 is not present.Controller 14 uses this change in voltage to determine the presence of aconductive object in proximity to sensor 12. An apparent change incapacitance can also be observed when a non-conducting but dielectricobject is brought near the sensor or a statically charged object isbrought near the sensor.

Alternately, if object 16 is non-conductive, has poor conductiveproperties, is not a sufficiently strong dielectric, is not sufficientlystatically charged, or is conductive yet too small to develop asignificantly large capacitance between itself and first conductor 450,then a secondary means of object sensing exists within sensor 12 fordetecting such an object 16. This secondary means is the pinch sensingaspect of sensor 12 and occurs when an object 16 makes contact with thesensing surface of sensor 12. Upon such contact, first conductor 450 iscompressed towards second conductor 451 as a result of the force appliedagainst sensor 12 at its sensing surface by object 16. The resultingcompression of the two conductors 450, 451 towards one another increasesthe capacitance of sensor 12. This creates a change in the storedelectrical charge on sensor 12. Hence, the change in stored electricalcharge results in a different sensor input signal 21, 23 developed onsensor 12.

The value of charge storing capacitor 504 is typically fifty or moretimes greater than the capacitance of sensor 12. If only one capacitivecharge transfer was performed, resulting charge signal 513 generated oncharge storing capacitor 504 would be virtually immeasurable bymicro-controller 507. In order to develop a resulting charge signal 513that is large enough for processing, micro-controller 507 performs anumber of sequential charge transfers before measuring conditionedsignal 508 and before discharging charge storage capacitor 504. Thenumber of sequential charge transfers is nominally set at twenty.Resulting charge signal 513 is created by multiple charge transfers inthe summation of all sequential charge transfers made. When thesesequential charge transfers are performed rapidly, their resultingconditioned signal 508 is considered representative of the charge onsensor 12 at a single point in time. The sequential charge transfertechnique creates a natural amplification of sensor input signal 21, 23which increases the sensitivity of controller 14. This also doubles as ahigh-frequency noise filter by averaging multiple charge transfers madeover time.

Even with multiple charge transfers employed, an object approachingsensor 12 may produce variations in resulting charge signal 513 whichare too small for processing. Thus, controller 14 performs a number ofprocess steps using electronic stages 510, 509 to magnify resultingcharge signal 513 into conditioned charge signal 508 so thatmicro-controller 507 can measure the conditioned charge signal.

In order to magnify resulting charge signal 513, initial process stage510 performs a level shift on the resulting charge signal to remove mostof its DC component. Controller 14 employs a digital-to-analog circuit511 to produce a DC bias voltage signal 514. Initial process stage 510subtracts voltage offset signal 514 from resulting charge signal 513.Gain stage 509 amplifies the result to produce conditioned charge signal508. Conditioned charge signal 508 then represents a magnified view ofthe fluctuating sensor input signal 21, 23.

The ability of controller 14 to detect changes in sensor input signal21, 23 defines its sensitivity. The sensitivity of controller 14 isimportant for determining the characteristics of an object 16 as itapproaches or makes contact with sensor 12. Wide variations in sensorinput signal 21, 23 occur for objects 16 of differing conductivities,shapes, and sizes. Controller 14 is designed to adjust functionality asnecessary to maintain optimum sensitivity when measuring sensor inputsignal 21, 23.

By adjusting the number of charge transfers made during a chargetransfer sequence, the sensitivity of controller 14 can be modified.When the number of charge transfers is increased, the sensitivity ofcontroller 14 to sensor input signals 21, 23 increases. This is becauseeach charge transfer performed between sensor 12 and charge storingcapacitor 504 increases the magnitude of charge signal 513. Theresulting charge signal 513 becomes an amplified version of the originalcharge signal. By itself this strategy for increasing the sensitivity ofcontroller 14 is limited. As the voltage generated on charge storingcapacitor 504 approaches that of voltage source 501, the amount ofcharge transferred from sensor 12 to charge storing capacitor 504diminishes. Also, increasing the number of charge transfers extends thesampling time of controller 14 to sensor input signal 21, 23. Becauseresulting charge signal 513 represents the summation of all chargetransfers in a measurement, a greater number of charge transfers reducesinput noise appearing on sensor 12. Adjustment of the charge transfernumber is easily implemented by controller 14 either automatically or asa predefined software setup value.

Changing the value of charge storing capacitor 504 is another way ofadjusting the sensitivity of controller 14. Decreasing the capacitancecauses resulting charge signal 513 to become larger for the same numberof charge transfers while increasing it makes resulting charge signal513 smaller for the same number of charge transfers. The result is amodified relationship between the capacitances of sensor 12 and chargestoring capacitor 504.

Instead of a single charge storing capacitor 504, controller 14 couldemploy a bank of such capacitors 504 of similar or varying capacitancevalues combined in parallel and/or in series circuit configuration.Through software executed by the micro-controller 507 one or more ofthese capacitors 504 could be switched in-or-out of the circuit tochange the sensitivity of the system thereby forming an overall chargestoring capacitor 504 of the desired capacitive value.

Another way of optimizing the sensitivity of controller 14 is to changethe voltage applied to sensor 12 by voltage source 501. In this approachraising voltage signal 502 which is used to charge sensor 12 will yielda greater charge transferred to charge storing capacitor 504 during eachcharge transfer. Raising voltage signal 502 applied to sensor 12 raisesthe signal-to-noise ratio for sensor 12. This contributes to the overallfiltering and stability of controller 14 when taking measurements ofsensor input signal 21, 23. Voltage source 501 can be configured as aprogrammable voltage source thereby allowing micro-controller 507 toadjust the voltage potential used to charge sensor 12. Software executedby micro-controller 507 can then optimize its sensitivity to capacitancechanges on sensor 12 by adjusting the voltage source potential.

Another way to optimize the sensitivity of controller 14 is to changethe duration of time that switch 503 remains closed for charging sensor12. In this charge method, voltage source 501 acts more like a currentsource to meter the amount of charge delivered to sensor 12 while switch503 is closed. Configuring voltage source 501 for programmable constantcurrent operation can further enhance control over the charge procedureof sensor 12.

Another way to optimize the sensitivity of controller 14 to sensor inputsignal 21, 23 is to lower the reference voltage of an ADC withinmicro-controller 507 in order to increase the resolution of the ADC whenconverting the pre-conditioned sensor input signal 508 to a numericalvalue for processing.

In the preferred embodiment of controller 14 as discussed thus far withrespect to FIG. 71, charge storing capacitor 504 is referenced toground. An alternate circuit configuration references charge storingcapacitor 504 to a variable voltage source instead of ground. Whencharge developed in sensor 12 is transferred to charge storing capacitor504, the variable voltage source adjusts to maintain a virtual groundpotential at resulting charge signal 513. By doing so, each chargetransfer results in 100% of the charge stored in sensor 12 to betransferred to charge storing capacitor 504. When all charge transfersare complete, the resulting voltage across charge storing capacitor 504represents the summation of charge transfers. This method of chargetransfer carries the added benefit of equally weighted charge transfers.By transferring 100% of the charge developed in sensor 12, fewer chargetransfers are needed to produce a resulting charge signal 513 of greatenough magnitude. Fewer charge transfers also means that sensor 12 canbe read faster, thereby increasing response time of controller 14.

Any number of these methods of adjusting the sensitivity of controller14 can be used to enhance its ability to measure variations of sensorinput signal 21, 23.

As described above with reference to FIG. 71, micro-controller 507 ofcontroller 14 manages hardware operations and timing. Micro-controller507 performs a number of software algorithms or routines to detect,identify, and respond to objects 16 that approach or contact sensor 12.These software algorithms will now be described with reference to FIGS.72 through 78 with continual reference to FIG. 71.

With reference to FIG. 72, micro-controller 507 performs a windowmonitor software routine 700 in order to monitor sensor input signal 21,23 for detection of an object 16 to sensor 12. Window monitor softwareroutine 700 is executed when motor 18 is being driven to close atranslating device 20 such as a window. Initially, micro-controller 507responds to a command to close window 20 (i.e., close window command,decision step 701) by performing a calibrate system routine 702, asensor measurement routine 703, and a calculate trip threshold routine704. If the measurement of sensor input signal 21, 23 indicates that anobject 16 is in the movement path of window 20 during closure of thewindow (decision step 705), then micro-controller 507 aborts the closewindow command (step 706) and reverses motor 18 in order to retract thewindow (step 707) thereby releasing the object from possible entrapmentby the window.

FIG. 73 illustrates system calibration routine 702 performed bymicro-controller 507. System calibration routine 702 includes DACcircuit 511 setting the DC offset 514 to nominal (step 710) and thenmicro-controller 507 performing a read sensor input routine 711 in orderto read the conditioned resulting charge signal 508. If the conditionedresulting charge signal 508 is not within a suitable range (decisionstep 712), then DAC circuit 511 further adjusts the DC offset 514 (step713). This process is repeated until the conditioned resulting chargesignal 508 falls within the suitable range.

FIG. 74 illustrates sensor input signal measurement routine 703performed by micro-controller 507. Routine 703 includes micro-controller507 performing read sensor input routine 711 in order to read theconditioned resulting charge signal 508 and thereby measure thecapacitance of sensor 12.

FIG. 75 illustrates read sensor input routine 711 performed bymicro-controller 507 for measuring the capacitance of sensor 12. Routine711 initially includes micro-controller 507 closing switch 503 to placea known voltage 502 generated by voltage source 501 across conductors450, 451 of sensor 12 in order to charge the sensor (step 718).Micro-controller 507 then opens switch 503 to isolate sensor 12 fromvoltage source 501 and closes switch 505 in order to transfer theelectrical charge in the sensor to second charge storing capacitor 504(step 719). This process is repeated to perform multiple chargetransfers (decision step 720) such as twenty transfers as describedabove with reference to FIG. 71. The resulting charge left on chargestoring capacitor 504 (i.e., resulting charge signal 513) is then readby stages 510, 509 to produce conditioned signal 508 (step 721).Micro-controller 507 then reads conditioned signal 508 on its ADC inputto generate a sensor reading (step 722). The sensor reading isindicative of the capacitance of sensor 12 and micro-controller 507 usesthe sensor reading to determine the presence of an object 16 near sensor12.

The ADC input of micro-controller 507 converts the analog conditionedsignal 508 from sensor 12 into a numeral representation of sensor inputsignal 21, 23. The resolution of this ADC input defines the level ofsensitivity that micro-controller 507 has for measuring capacitancechanges on sensor 12. Several means of signal amplification areavailable as described above with reference to FIG. 71 in order toincrease the overall sensitivity of controller 14 to capacitance changesof sensor 12, and hence to be able to detect smaller variations insensor capacitance.

Micro-controller 507 is capable of executing software to adjust thesensitivity of controller 14 to changes in capacitance on sensor 12.Implementation of any number of signal amplification methods permitscontroller 14 to measure small capacitance changes of sensor 12 over alarge capacitance range.

Turning back to sensor measurement routine 703 shown in FIG. 74, withcontinual reference to FIGS. 71 and 75, micro-controller 507 storessensor readings (step 714) after they are taken (read sensor routine711). Once a number of sensor readings are taken (decision step 715)micro-controller 507 performs a filter rule routine 716 on the sensorreadings to create a filtered sensor measurement (step 717).Micro-controller 507 uses the filtered sensor measurement to determinethe capacitance change on sensor 12, and then uses the sensorcapacitance change to determine the presence of an object 16 near sensor12. The application of digital filtering rules (routine 716) assists inremoving noise from sensor measurement (step 717) and to extract usefulcharacteristics about sensor input signal 21, 23.

As such, sensor measurement routine 703 stores sequential sensorreadings in step 714 for use in generating a sensor measurement in step717. As the sensor readings are performed they are stored in memory atstep 714 and the oldest sensor reading is discarded. Any number ofsequential sensor readings such as ten sequential sensor readings can besummed to represent a single sensor measurement 717. Summing sensorreadings 722 in step 714 acts to filter out noise and provides someadditional resolution of sensor input signal 21, 23. Alternately, otherfiltering rules or averaging can be used, such as digital multi-pointaveraging, or raw sensor readings 722 could be used unfiltered.

A nominal input value of sensor input signal 21, 23 is derived fromsensor signal measurement routine 703. Calculate trip threshold routine704 (FIG. 72) calculates a trip threshold value relative to the nominalinput value. If the value of sensor input signal 21, 23 rises above thetrip threshold value, then micro-controller 507 declares an obstruction(step 705—FIG. 72) in the way of window 20.

Changes in humidity and temperature, and the presence or absence ofsnow, rain, or dirt can cause variations in sensor input signal 21, 23.Drift compensation is implemented to counteract these differences formedbetween the sensor input value and the nominal input value. The nominalinput value is adjusted up or down at independent rates to maintainvalue with the sensor input signal as the sensor input signal drifts.The speed at which the nominal input value can track the value of thesensor input signal is limited to prevent filtering out detection ofvalid obstructions. Alternatively, controller 14 can measure thetemperature and/or humidity, and alter the nominal and/or trip valuesbased on those measurements.

Controller 14 incorporates EEPROM (writable non-volatile) memory that incertain embodiments is used to store operating parameters and constants.This permits controller 14 to enable, disable, or select specificalgorithms and/or behaviors, and/or be tuned to specific applicationswithout requiring changes to executable code. In other embodiments,these parameters can be modified by adaptive algorithms so controller 14can adjust to changing conditions in a manner transparent to users. Forexample, if adaptive algorithms determine that the dynamic range ofsensor input signal 21, 23 is too small, then micro-controller 507 canincrease the number of charge transfer operations performed for eachsensor sample. If this change improves the response of controller 14,the EEPROM can be updated to reflect this change and the system canavoid having to make this adaptation every time it is started, andfurther adaptations can be continued from the new baseline.

In the exemplary controller 14, the width of each pulse injected intosensor 12 during a charge transfer is identical to each of the others.An alternate embodiment varies the pulse width in order to spread thespectrum of radiated emissions and thus improve EMI characteristics.Other strategies to improve EMI include varying the period betweenmeasurements of sensor 12, and disabling the sensor during periods whencontroller 14 is unconcerned about possible obstructions, such as anytime the translating panel is not in motion.

For improved EMI susceptibility, the calculated trip threshold value israised when sensor input signal 21, 23 becomes noisy. It is based on themin and max values recorded within a set number of cycles and the numberof nominal value crossings that occur within the sample group. Highnoise levels will raise the signal level required to detect anobstruction 16.

In the presence of certain kinds of electrical noise, sensor inputsignal 21, 23 changes very quickly by large amounts. Software filteralgorithms permit the controller 14 to ignore these offsets while stillcorrectly detecting and reporting actual obstructions. In one embodimentof the present invention, an obstruction 16 is reported only aftercontroller 14 observes several (such as six) step changes in sensorinput signal 21, 23. At each step, the nominal value is adjusted tocompensate for the rise in sensor input signal 21, 23. In this way,large step values due to the application of electrical noise do not bythemselves cause sensor 12 to declare an obstruction 16 is present.Sensor input signal 21, 23 must continue to rise for each of thesubsequent steps required to detect obstruction 16. If sensor inputsignal 21, 23 does not progress through the remaining steps within aparticular period of time (nominally one second), the step count isdecremented or reset to accommodate the environmental change. In thisway, sensor input signals 21, 23 that rise too quickly and fail tocontinue to rise are ignored. Another embodiment directly measures theslope of the change of sensor input signal 21, 23 with each newmeasurement and adjusts the nominal value to eliminate that portion ofthe sensor input signal that could not come from a legitimateobstruction.

Besides operating as an obstruction detecting sensor, the exemplarycontroller 14 also monitors switch inputs, translates those inputs intouser commands, controls motor 18 which drives a translating panel 20,and communicates with other controllers to provide operating anddiagnostic reports.

The exemplary controller 14 uses four switch inputs. The switch inputscan be configured active high or active low in EEPROM. The function ofeach switch is also assigned in EEPROM: Open, Close, Auto Open, and AutoClose. Pressing the Open or Close switches alone is interpreted as aManual Open or Manual Close command, respectively. Releasing the switchterminates the Manual Open or Close command. Pressing Open with AutoOpen initiates an Express Open command, which causes controller 14 toopen translating panel 20 until motor 18 stalls, end of travel isreached, or the command is terminated by pressing any switch. Any othercombination of switch presses are interpreted as a “Stop” command whichhalts any motion of translating panel 20.

The Auto Open and Auto Close switches are optional. If an Auto switch isnot defined, the corresponding Express command is initiated by a “tap”on the appropriate switch, e.g., if Auto Open is not defined “tapping”the Open switch initiates the Express Open command. A “tap” is definedas any press whose duration is less than the amount of time specified inEEPROM, nominally 400 ms. A press longer than the defined tap time isinterpreted as a Manual command.

Alternatively, user commands could be issued to controller 14 thoughcommunications interfaces, or the controller could perform autonomously,opening or closing panel 20 when required, e.g., when rain was detected.

If an obstruction 16 is detected while translating panel 20 is closing,controller 14 retracts the panel to release the entrapped object. In theexemplary system, the length of the retraction is defined in EEPROM asthe amount of time motor 18 is reversed. Alternate embodiments userelative window positions as reported by motor Hall-effect sensors orencoders. One particular system retracts the window a specific length(nominally 10 cm) or to a specific position (nominally the halfwaypoint), whichever is greater. In any case, any new user commands areignored while window 20 is retracting. A stall of motor 18 ortranslating panel 20 reaching the end-of-travel will also terminate theretraction.

A manual override can be provided to permit the user to close panel 20even if an obstruction 16 is detected. In the exemplary system, themanual override is activated by issuing a manual close command duringwhich an obstruction 16 is detected, holding that command through theretraction until it is complete, then issuing two more manual closecommands within one second. The second manual close is interpreted asthe override, and controller 14 will drive translating panel 20 closeduntil the command is terminated.

When the user commands that translating panel 20 close, obstructionsensor 12 is calibrated to find the optimal operating parameters beforemoving the panel. The calibration may be limited to a few or even justone parameter in order to minimize any delay. If sensor 12 is detectingan obstruction 16 before the calibration is performed, the obstructionis reported (causing panel 20 to retract), but is calibrated out, so anysubsequent command to close the panel may be honored. Alternately, thesystem may refuse to calibrate out an existing obstruction, particularlyif the measured magnitude of the obstruction is large. This will preventa sensor 12 that is saturated from failing to detect a valid obstruction16.

Referring now to FIG. 76, with continual reference to FIG. 71, a motormonitor routine 740 performed by micro-controller 507 is shown. Motormonitor routine 740 is performed upon micro-controller 507 producing amotor signal 512 to rotate motor 18 in order to move translating device20. Micro-controller 507 performs motor monitor routine 740 to monitormotor signal 512. From information gathered by motor monitor routine740, micro-controller 507 is able to compute operating performance andstatus information about motor 18 and translating device 20.

As such, micro-controller 507 performs motor monitor routine 740 whenmotor 18 is being driven (decision step 741). If motor 18 has timed-out(decision step 742) of if the motor has stalled (decision step 743),then micro-controller 507 stops producing motor signal 512 (step 745).If motor 18 has not timed-out (decision step 742), then micro-controller507 performs a motor current routine 750 (shown in FIG. 77). Uponperforming motor current routine 750 micro-controller 507 then performsa motor commutation routine 760 (shown in FIG. 78). Micro-controller 507then determines if motor 18 has stalled (decision step 743) or if themotor has overheated (decision step 744). If any of these last twoconditions are positive, then micro-controller 507 stops producing motorsignal 512 in order to stop motor 18 (step 745). Micro-controller 507repeats the process of motor monitor routine 740 while motor 18 is beingdriven to move translating device 20.

Referring now to FIG. 77, with continual reference to FIGS. 71 and 76,motor current routine 750 is shown. Motor current routine 750 includesmicro-controller 507 measuring the motor current (step 751) anddetermining if the motor current is high (decision step 752). High motorcurrent can indicate that motor 18 is stalled (step 755) or is beingheavily loaded by translating device 20. If micro-controller 507determines that an obstruction 16 is present (decision step 753) in thepath of translating device 20, then micro-controller 507 attributes thehigh motor current to the obstruction. Otherwise, the high motorcurrent, in the absence of an obstruction 16, is interpreted bymicro-controller 507 as translating device 20 having reached itsend-of-travel position (decision step 754), such as either being fullyopened or fully closed. Conversely, detection of low motor current(decision step 756) can be an indication that motor 18 is overheated(step 757) or otherwise damaged.

Referring now to FIG. 78, with continual reference to FIGS. 71 and 76,motor commutation routine 760 is shown. Motor commutation routine 760includes micro-controller 507 measuring motor commutation pulses (step761). As motor 18 rotates to move translating device 20,micro-controller 507 monitors electrical pulses 19 generated at thecommutator inside the motor. Micro-controller 507 monitors theoccurrence of motor commutation pulses (step 761) coming from motor 18to determine whether or not the motor is rotating. The presence of motorcommutation pulses (decision step 762) confirms rotation by motor 18,and hence movement by translating device 20. The rate at whichcommutation pulses occur is used by micro-controller 507 to calculatemotor speed (step 763).

Micro-controller 507 uses the motor speed information in combinationwith motor current to determine the operating load conditions on motor18. This information can be used to determine conditions such as motorstall, end-of-travel, or an otherwise undetected obstruction, especiallywhen used in conjunction with a measurement of the motor drive current.Commutation pulse counting allows micro-controller 507 to track therelative position of translating device 20 (step 764). Positioninformation can be used to predict an end-of-travel occurrence oftranslating device 20 and to ignore the portion of capacitance sensorinput signal 21, 23 due to the approach of the translating device orsealing surface as the device closes over the opening.

In a similar embodiment, the monitoring of motor commutation pulses maybe substituted with an alternate signal 19. Such a signal 19 can bederived from pulse generating circuitry such as Hall-Effects, opticalencoders, or other such position sensing devices that can detect therotation of the rotor of motor 18. Improved speed and positioninformation can be attained when motor 18 is fitted with positiveposition sensors, like Hall-effect sensors, arranged in an appropriateconfiguration, such as a quadrature. Such a configuration provides motor18 direction information as well as a more reliable signal 19 for pulsedetection. The end result is simpler processing and more accurateposition, speed, and direction information.

If no pulses are detected after a period of motor operating time(decision step 765), then it is determined that motor 18 is stalled(step 766), or is otherwise unable to rotate. When a stall is detected(step 743 of motor monitor routine 740), power to motor 18 is removed(step 745 of motor monitor routine 740). Likewise, if motor 18 isdetected as overheated (step 744 of motor monitor routine 740), power tothe motor is removed (step 745 of motor monitor routine 740). Stoppingmotor 18 helps to protect it from further overheating. Additional motorprotection is provided by the application of a movement timer (step 742of motor monitor routine 740). The timer operates whenever motor 18 ispowered (step 741 of motor monitor routine 740). The maximum time fortranslating device 20 to fully traverse from one end-of-travel toanother is determined by micro-controller 507. If the timer reaches thistime value before motor 18 is stopped (step 741 of motor monitor routine740), either by user command, limit switch, stall detection, or othermeans, power is removed from the motor (step 745 of motor monitorroutine 740). Prolonged operation of motor 18 may indicate a damaged orimproperly working translating device 20 or possibly an undetectable orunforeseen operating condition.

To reduce power consumption and emitted electrical noise, an embodimentof the invention disables some or all of the processing functions ofcontroller 14 when translating panel 20 is not in motion or the systemis otherwise unconcerned about possible obstructions to the panel. Oneembodiment simply interrogates sensor 12 only when translating panel 20is actually closing. A more complex embodiment disables an oscillator ofmicro-controller 507 whenever the system is idle, and remains in thatstate until the user issues a new command.

While the present invention has been described in conjunction withspecific embodiments thereof, it is evident that many alternatives,modifications, and variations will be apparent to those skilled in theart in light of the foregoing description. Accordingly, it is intendedto embrace all such alternatives.

1. An anti-entrapment system for preventing objects from being entrappedby a translating device, the system comprising: a capacitance sensorpositioned adjacent to a translating device, the capacitance sensorhaving first and second conductors separated by a separation distanceand a compressible dielectric element interposed between the conductors,the conductors having a capacitance dependent upon the separationdistance; wherein the capacitance of the conductors changes in responseto a geometry of the capacitance sensor changing as a result of at leastone of the conductors and the dielectric element deforming in responseto a first object touching the capacitance sensor; wherein thecapacitance of the conductors changes in response to a second conductiveobject coming into proximity with at least one of the conductors.
 2. Thesystem of claim 1 further comprising: a controller for controlling thetranslating device as a function of the capacitance of the conductors inorder to prevent the translating device from entrapping either object.3. The system of claim 1 further comprising: analysis means forgenerating an indication upon either the first object touching thecapacitance sensor or the second conductive object being in theproximity of the capacitance sensor.
 4. The system of claim 1 wherein:at least one of the conductors is sufficiently flexible so as to allowlocal deformation of the at least one of the conductors and thedielectric element in a region of the capacitance sensor being touchedby the first object.
 5. The system of claim 1 wherein: at least one ofthe conductors is malleable so as to be able to take and retain a bendor a twist in response to sufficiently large forces applied to thecapacitance sensor in order to permanently bend or twist the capacitancesensor into a predetermined shape.
 6. The system of claim 1 wherein: atleast one of the conductors has a serpentine pattern.
 7. The system ofclaim 1 wherein: at least one of the conductors is a conductive film. 8.The system of claim 1 wherein: at least one of the conductors is aconductive paint.
 9. The system of claim 1 wherein: at least one of theconductors includes a dopant added to a portion of the dielectricelement so as to form a conductive region on the dielectric element. 10.The system of claim 1 wherein: one of the conductors is wider than theother conductor.
 11. The system of claim 10 wherein: the wider conductoris electrically grounded and an electric potential is applied to thenarrower conductor such that the capacitance sensor has a directionalproximity sensitivity to conductive objects.
 12. The system of claim 10wherein: the narrower conductor is electrically grounded and an electricpotential is applied to the wider conductor such that the capacitancesensor has a directional proximity sensitivity to conductive objects.13. The system of claim 1 wherein: an electric polarity of thecapacitance sensor is alternated.
 14. The system of claim 13 furthercomprising: analysis means to compare signals of the capacitance sensorat each polarity so as to distinguish between the second conductiveobject being proximally detected from the first object being touchdetected.
 15. The system of claim 1 wherein the capacitance sensor ismounted to a structure, the system further comprising: a third conductorplaced between the capacitance sensor and the structure; and a firstnon-conducting element interposed between the capacitance sensor and thethird conductor.
 16. The system of claim 15 further comprising: a secondnon-conducting element interposed between the third conductor and thestructure.
 17. The system of claim 15 wherein: one of the first andsecond conductors is closer to the structure than the other one of thefirst and second conductors, and the one of the first and secondconductors closest to the structure and the third conductor are bothelectrically grounded.
 18. The system of claim 1 wherein: one of thefirst and second conductors is closer to the structure than the otherone of the first and second conductors, and the one of the first andsecond conductors closest to the structure and the third conductor areboth applied with a non-zero electrical voltage.
 19. The system of claim1 wherein: at least one of the conductors is segmented into a pluralityof conductively isolated conductor segments.
 20. The system of claim 19further comprising: means to extract signals from each of the conductorsegments so as to develop an indication from each these conductorsegments related to an apparent capacitance observed at each of theseconductor segments.
 21. The system of claim 20 further comprising:analysis means to analyze a pattern of signals from the conductorsegments so as produce an indication of a width along the capacitancesensor of a detected object.
 22. The system of claim 20 furthercomprising: analysis means to analyze a pattern of signals from theconductor segments so as to produce an indication of a force applied bythe first object to the capacitance sensor upon the first objecttouching the capacitance sensor.
 23. The system of claim 1 wherein: awidth of at least one of the conductors is varied in at least onelocation along the capacitance sensor so as to alter sensitivity of thecapacitance sensor at the at least one location.
 24. The system of claim1 wherein: a thickness of the compressible dielectric element is variedin at least one location along the capacitance sensor so as to altersensitivity of the capacitance sensor at the at least one location. 25.The system of claim 1 wherein: an angle between the conductors is variedin at least one location along the capacitance sensor so as to altersensitivity of the capacitance sensor at the at least one location. 26.The system of claim 1 wherein: one the conductors partially surroundsthe other conductor so as to produce a directional sensitivity orinsensitivity to the proximity of the second conductive object to thecapacitance sensor.
 27. The system of claim 26 wherein: a relativelocation and orientation of the first conductor with respect to arelative location and orientation of the second conductor is varied inat least one location along the capacitance sensor so as to altersensitivity of the capacitance sensor at the at least one location. 28.The system of claim 1 wherein: the conductors are incorporated within acompliant layer such as a weather seal on an edge of an opening of thetranslating device.
 29. The system of claim 28 wherein: the conductorsare incorporated within the compliant layer during extrusion forming ofthe compliant layer.
 30. The system of claim 28 wherein: at least one ofthe conductors is sufficiently malleable and of sufficient thickness andstrength so as to be bendable into a desired shape and to retain thatshape after bending while being sufficiently difficult to bend so as toretain that shape even if bent after incorporation in the compliantlayer in the presence of restoring forces exerted by the compliant layerafter the compliant layer has been bent by the at least one of theconductors or is in a process of bending the at least one of theconductors.
 31. The system of claim 28 wherein: at least a portion ofthe compliant layer is interposed between the conductors so as to act asthe compressible dielectric element.
 32. The system of claim 28 wherein:at least one of the conductors is flexible and in a portion of thecompliant layer that is sufficiently compliant so as to allow acapacitively detectable deformation of the flexible conductor inresponse to touch of the first object upon the capacitance sensor beforea pre-determined undesirable amount of force can be developed on thefirst object through the touch.
 33. An anti-entrapment system forpreventing objects from being entrapped by a translating device, thesystem comprising: a capacitance sensor positioned adjacent to atranslating device, the capacitance sensor having first and secondconductors separated by a separation distance and a compressibledielectric element interposed between the conductors, the conductorshaving a capacitance dependent upon the separation distance; wherein thecapacitance of the conductors changes in response to a geometry of thecapacitance sensor changing as a result of at least one of theconductors and the dielectric element deforming in response to a firstobject touching the capacitance sensor; wherein the capacitance of theconductors changes in response to a second conductive object coming intoproximity with at least one of the conductors; and a controller forreceiving a signal from the capacitance sensor indicative of thecapacitance of the conductors, wherein the controller controls thetranslating device as a function of the capacitance of the conductors inorder to prevent the translating device from entrapping either object.34. The system of claim 33 wherein: the controller generates anelectrical charge on the conductors.
 35. The system of claim 34 wherein:the controller varies an amount of electrical charge generated acrossthe conductors.
 36. The system of claim 34 wherein: the controllertransfers electrical charge on the conductors to a charge storing devicefor the charge storing device to capture, wherein the electrical chargecaptured by the charge storing device is the signal from the capacitancesensor indicative of the capacitance of the conductors.
 37. The systemof claim 36 wherein: the charge storing device is a capacitor.
 38. Thesystem of claim 36 wherein: the controller varies capacitance of thecharge storing device.
 39. The system of claim 36 wherein: thecontroller measures a magnitude of the electrical charge captured by thecharge storing device, wherein the measured magnitude of the electricalcharge captured by the charge storing device is the signal from thecapacitance sensor indicative of the capacitance of the conductors. 40.The system of claim 39 wherein: the controller generates an offsetsignal to bias the magnitude of the electrical charge captured by thecharge storing device.
 41. The system of claim 36 wherein: thecontroller amplifies a magnitude of the electrical charge captured bythe charge storing device, wherein the amplified magnitude of theelectrical charge captured by the charge storing device is the signalfrom the capacitance sensor indicative of the capacitance of theconductors.
 42. The system of claim 36 wherein: the controller generatesan electrical charge on the conductors multiple times and transferselectrical charge on the conductors to the charge storing device eachtime for the charge storing device to capture, wherein the summedelectrical charge captured by the charge storing device is the signalfrom the capacitance sensor indicative of the capacitance of theconductors.
 43. The system of claim 42 wherein: the controller executesan adaptive threshold detection algorithm on the signal from thecapacitance sensor in order to measure the capacitance of theconductors.
 44. The system of claim 43 wherein: the controller executessoftware to vary the number of electrical charge transfers from theconductors to the charge storing device in order to improve sensitivityof the controller when the controller measures the capacitance of theconductors.
 45. The system of claim 44 wherein: the controller variesthe number of electrical charge transfers from the conductors to thecharge storing device in order to amplify the measured capacitance ofthe conductors.
 46. The system of claim 43 wherein: the controllerexecutes software to reduce a DC component of the signal from thecapacitance sensor improve sensitivity of the controller to the measuredcapacitance of the conductors.
 47. The system of claim 36 wherein: thecontroller executes software to change capacitance of the charge storingdevice in order to improve sensitivity of the controller in measuringthe capacitance of the conductors.
 48. The system of claim 33 wherein:the controller retracts the translating device upon the controllerdetecting an object touching the capacitance sensor or in proximity ofthe capacitance sensor in order to prevent entrapment of the object bythe translating device and allow the object to be moved freely away fromthe translating device.
 49. The system of claim 33 wherein: thecontroller executes an override of preventing the translating devicefrom entrapping either object upon command from an operator.
 50. Thesystem of claim 33 wherein: the controller executes automaticcalibration procedures upon controlling the translating device to movein a manner that potentially results in entrapment of either object bythe translating device.
 51. The system of claim 33 wherein: thecontroller executes shutdown of movement of the translating device whenthe translating device is stationary.
 52. The system of claim 33wherein: the controller executes software that determines stall of amotor that is being used to move the translating device.
 53. The systemof claim 33 wherein: the controller executes software to monitor motorcommutator pulses of a motor that is being used to move the translatingdevice.
 54. The system of claim 33 wherein: the controller executessoftware to monitor position of the translating device.
 55. The systemof claim 33 wherein: the controller executes software to monitor speedof the translating device as the translating device moves.
 56. Thesystem of claim 33 wherein: the controller includes Hall-Effect sensors.57. The system of claim 33 wherein: the controller enters a power savingmode when the system is idle.
 58. The system of claim 36 wherein: thecontroller performs multiple sequential electrical charge transferoperations in a given time period in order to simultaneously amplify andfilter the signal indicative of the capacitance of the conductors. 59.The system of claim 36 wherein: the charge storing device includes abank of charge storing devices, wherein the controller connects the bankof charge storing devices in parallel, series, or a combination ofparallel and series in order to improve sensitivity of the controllerwhen the controller measures the capacitance of the conductors.
 60. Thesystem of claim 59 wherein: the charge storing devices have varyingcharge storing values.
 61. The system of claim 39 wherein: thecontroller generates an electrical charge on the conductors by applyinga voltage to the conductors, wherein the controller varies the voltageapplied to the conductors in order to adjust sensitivity of thecontroller in measuring the magnitude of the electrical charge capturedby the charge storage device.
 62. The system of claim 39 wherein: thecontroller generates an electrical charge on the conductors by applyinga voltage pulse to the conductors, wherein the controller variesduration of the voltage pulse in order to adjust sensitivity of thecontroller in measuring the magnitude of the electrical charge capturedby the charge storage device.
 63. The system of claim 62 wherein: thecontroller generates an electrical charge on the conductors multipletimes by applying voltage pulses to the conductors, wherein thecontroller varies width of the voltage pulses such that the voltagepulses provide a total injected electrical charge on the conductors. 64.The system of claim 63 wherein: the controller compensates for thevarying injected electrical charge mathematically.
 65. The system ofclaim 63 wherein: the controller varies time at which the voltage pulsesare applied to the conductors.
 66. The system of claim 42 wherein: thecontroller uses a boxcar average of the summed electrical chargecaptured by the charge storage device to simultaneously increase theresolution of and filter the signal from the capacitance sensorindicative of the capacitance of the conductors.
 67. The system of claim66 wherein: the controller varies amount of time between individualsamples of the electrical charge transferred from the conductors to thecharge storage device.
 68. The system of claim 67 wherein: thecontroller varies the amount of time between individual samples of theelectrical charge transferred from the conductors to the charge storagedevice in order to spread a radiated spectrum of the summed electricalcharge captured by the charge storage device.
 69. The system of claim 33wherein: the controller determines presence or absence of an object inproximity to the capacitance sensor as a function of deviation about anominal value of the signal from the capacitance sensor.
 70. The systemof claim 69 wherein: the controller adjusts the nominal value to driftwith signals from the capacitance sensor over time in order to preventchanging environmental conditions from being falsely interpreted by thecontroller as being an object in the presence of the capacitance sensor.71. The system of claim 70 wherein: the controller adjusts the nominalvalue in response to noise in order to improve performance of thecontroller in receiving the signal from the capacitance sensor in thepresence of noise.
 72. The system of claim 33 wherein: the controllerrequires a quickly rising or falling signal from the capacitance sensorto continue rising or falling prior to controlling the translatingdevice as a function of the signal in order to prevent noise fromfalsely being interpreted by the controller as being an object in thepresence of the capacitance sensor.
 73. The system of claim 72 wherein:the controller calculates a derivative of the signal from thecapacitance sensor in order to determine if the signal is rising orfalling quickly.
 74. The system of claim 33 wherein: the controllermeasures environmental parameters such as temperature and humidity inorder to compensate the signal from the capacitance sensor for thechanging environmental conditions.
 75. The system of claim 33 wherein:the controller uses EEPROM to store operating parameters for thecapacitance sensor and for the translating device.
 76. The system ofclaim 75 wherein: the controller uses the EEPROM to select, enable, ordisable particular algorithms for processing the signal from thecapacitance sensor.
 77. The system of claim 75 wherein: the controlleruses the EEPROM to configure location and interpretation of controlinputs for the translating device.
 78. The system of claim 75 wherein:the controller uses adaptive algorithms that modify values in EEPROM tofacilitate long-term adaptations to the signal from the capacitancesensor.
 79. The system of claim 33 wherein: the controller monitorspositions of switches, dials, or levers over time such that thecontroller interprets the positions of the switches, dials, or levers asuse commands for controlling the translating device.
 80. The system ofclaim 33 wherein: the controller receives user commands for controllingthe translating device from a serial or parallel communicationsinterface.
 81. The system of claim 33 wherein: the controller monitorsambient conditions to control the translating device autonomously. 82.The system of claim 33 wherein: the controller controls the translatingdevice by controlling a motor which powers the translating device. 83.The system of claim 82 wherein: the controller uses motor drive currentto calculate motor load and determine whether the motor has stalled. 84.The system of claim 82 wherein: the controller counts motor commutatorpulses to determine motor speed and position which is indicative oftranslating device speed and position.
 85. The system of claim 82wherein: the controller uses Hall-effect sensors to determine motorspeed, direction, and position.
 86. The system of claim 33 wherein: thecontroller uses translating device speed, position, and directioninformation to calculate expected contribution to the signal from thecapacitance sensor upon the signal indicating the presence of an objectin proximity to the capacitance sensor and then compensates for signalas a function of the calculated expected contribution.
 87. The system ofclaim 33 wherein: the controller retracts the translating device toenable an object to be released from entrapment by the translatingdevice.
 88. The system of claim 33 wherein: the controller is operableto close the translating device in the presence of an object to thecapacitance sensor.
 89. The system of claim 33 wherein: the controllercalibrates operating parameters of the capacitance sensor each time thetranslating device is closed.
 90. The system of claim 89 wherein: thecontroller prevents calibration of the capacitance sensor if thepresence of an object to the capacitance sensor was being detectedbefore the calibration and magnitude of the signal indicative of thepresence of the object to the capacitance sensor is sufficiently large.91. The system of claim 89 wherein: the controller allows calibration ofthe capacitance sensor but prevents the translating device from closingif the presence of an object to the capacitance sensor was beingdetected before the calibration.
 92. The system of claim 89 wherein: thecontroller calibrates the capacitance sensor and allows the translatingdevice to close if the presence of an object to the capacitance sensorwas being detected before the calibration and magnitude of the signalfrom the capacitance sensor indicative of the presence of the object tothe capacitance sensor is sufficiently small.